Answer Key and Theory for MP-1918-2S_053379/MP-1918-2D_053380 CAN Bus Multiplex System Trainer 91-MP-1918-2S_REVB © ConsuLab Educatech Inc, 2025. All rights reserved. Teacher only 91-MP-1918-2 Table of contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 2 Table of Contents MP-1918 CAN bus Multiplex Trainer Introduction 5 General Information 8 Connecting the power supply to the Moduponent™ panels 9 The Theory and Operation of CAN 11 Student CAN bus Theory Test Answer Key Student CAN bus Theory Test 27 Student CAN bus Theory Test Answer Key 30 Student Assignments Answers SA-1 — Wiring the MP-1918 Ground Circuits 32 Wiring Diagram Answer Key 33 Instructor Answer Key 34 SA-2 — Testing the MP-1918 Load Circuits 35 Wiring Diagram Answer Key 36 Instructors Answer Key 37 SA-3 — Wiring the MP-1918 Remaining Ground Circuits 38 Wiring Diagram Answer Key 39 SA-4 — Wiring the MP-1918 Module Circuits 40 Wiring Diagram Answer Key 41 SA-5 — Wiring the MP-1918 Input Circuits 42 Wiring Diagram Answer Key 43 SA-6 — Wiring the MP-1918 B+ Load Circuits 44 Wiring Diagram Answer Key 45 91-MP-1918-2 Table of contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 3 SA-7 — Wiring the MP-1918 CAN bus Communication Circuits 46 Wiring Diagram Answer Key 48 Instructor Answer Key 49 SA-8 — Basic CAN bus Function 50 Instructor Answer Key 51 SA-9 — MP-1918 Viewing a CAN Low Packet of Information 52 Instructor Answer Key 53 SA-10 — MP-1918 Viewing a CAN High Packet of Information 54 Instructor Answer Key 55 SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel DSO 56 Instructor Answer Key 57 SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO 58 Answer key 59 SA-13 — MP-1918 Digital to Analog Control 60 Instructor Answer Key 61 SA-14 — MP-1918 Input Module Inputs 62 Instructor Answer Key 63 SA-15 — MP-1918 CAN Cluster Module inputs 64 Instructor Answer Key 65 SA-16 — MP-1918 ECM Inputs 66 Instructor Answer Key 67 SA-17 — MP-1918 Engine Control Module Inputs — Part 1 68 Instructor Answer Key 69 SA-18 — MP-1918 Engine Control Module Inputs — Part 2 70 Instructor Answer Key 71 91-MP-1918-2 Table of contents 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada consulab.com info@consulab.com Toll-free: +1 (800) 567-0791 USA: +1 (810) 222-4525 Canada: +1 (418) 688-9067 Fax: +1 (418) 843-3444 4 © ConsuLab Educatech Inc, 2025. All rights reserved. No part of this work may be reproduced or transmitted in any form by any means, electronic, mechanical, including photocopying and recording, or by any information storage or retrieval system, without written permission from the publisher. Printed in Canada. The content of this manual is applicable to models 053379 and above. SA-19 — MP-1918 Engine Control Module Inputs — Part 3 72 Instructor Answer Key 73 SA-20 — MP-1918 CAN bus Activity 74 Instructor Answer Key 75 Student Assessment Answer Key Student Assessment 77 Instructor Answer Key 80 MP-1918 Wiring Template 81 Instrument Cluster Module Schematic With Faults 82 Input Module Schematic With Faults 83 Engine Control Module Schematic With Faults 84 Output Module Schematic With Faults 85 CAN bus System Schematic With Faults 86 consulab.com info@consulab.com 5 91-MP-1918-2 MP-1918 CAN bus Multiplex Trainer Introduction MP-1918 CAN bus Multiplex Trainer Introduction The MP-1918 CAN bus Multiplex Trainer is a state-of-the-art trainer designed to give the feel of a vehicle and some of its diagnostic capabilities in a classroom atmosphere. It consists of 4 modules that are communicating on a common bus. They are the instrument cluster module, the input module, the engine control module and the output module. The design of the trainer allows for an easy transition to a vehicle. By using this trainer in a classroom, you will be able to discuss, demonstrate, and test comprehension on the following: A. CAN wake up signal B. A variety of analog input signals C. A variety of analog output signals involving vehicle lighting D. Digital PCM input and output signals E. Scan data which will be seen on the instrument cluster. The cluster will double as a J-1939 communication device like a scanner. Each trainer has its own display without the need for connecting a scanner. F. Communication along the bus G. Wiring of a CAN bus H. Wiring a variety of circuits I. A series of light bulb “loads” that are controlled by the controller network. They include, Tail, Brake, Turn, Clear- ance, License plate and Backup lights. The trainer includes a built-in break-out box (BOB) with test points, allowing a digital multimeter (DMM) or digital storage oscilloscope (DSO) to be connected for circuit analysis readings. Additionally, the trainer contains a fault box which can be used to introduce up to 12 faults into the system for diagnos- tic purposes. Diagnosis can then be taught using a DMM or a DSO. The fault box can be locked in fault mode with no external indication of which fault(s) has been introduced. This allows for comprehensive testing by a student/technician. The MP-1918-95 Student Assignments will outline a series of lab activities that a student can accomplish to better his understanding of a CAN bus system. The trainer is wired with both a Deutsch connector, which is used in heavy vehicle applications and a data link connector (DLC), used in automotive applications. Either connector will allow the instructor or student to “see” the various signals by using a DMM or a DSO. Scan data that is usually available at a DLC or Deutsch connector can be displayed on the instrument cluster. This allows the live reading of various inputs such as coolant temp or throttle position, without the need to connect a scan tool. All pins that are used in each of the 4 modules have a breakout box equipped with slightly smaller 2mm size connectors. This prevents the student from making power and ground connections with the circuit jumper wires to the wrong pins of the modules. The break out box allows for the connection of a DMM or a DSO so signal patterns related to inputs, outputs or the CAN bus can be viewed. This makes the CAN bus Multiplex trainer an excellent tool, to not only teach inputs and outputs, but also for DSO operation. Students can demonstrate their DSO abilities, save a pattern and show it to their instructor for grading purposes. consulab.com info@consulab.com 6 91-MP-1918-2 MP-1918 CAN bus Multiplex Trainer Introduction The MP-1918 CAN bus Multiplex trainer is made up of three electrical Moduponent™ panels. A Moduponent™ is a Con- suLab patented design consisting of electrical components and connection terminals attached to a clear Plexiglas panel. Moduponents are designed to be attached to a portable frame with attachment pins. Each Moduponent™ has connec- tion terminals for the attachment of jumper wires by students to complete various electrical assignments designed to teach the operational concepts of the Moduponents™. Moduponents™ are available in various configurations covering many automotive and heavy vehicle systems. The top Moduponents™, with the display module, contains a fault box by which selected system faults can be inserted into the system for student learning of diagnostic and troubleshooting strategies. In the case of the MP-1918, the single sided trainer is made up of three Moduponents™ : • One (1) MP-1918-01 Moduponent™ with the display module MP-1918-01 Moduponent™ • One (1) MP-1918-02 Moduponent™ with the CAN bus MP-1918-02 Moduponent™ • One (1) HV-1918-03 Moduponent™ with the light bulbs as loads HV-1918-03 Moduponent™ consulab.com info@consulab.com 7 91-MP-1918-2 MP-1918 CAN bus Multiplex Trainer Introduction The Moduponent™ 03 contains the outputs (lights) that will be controlled off of the trainer. These lights will allow for immediate visual feedback that a particular circuit is functional. Students will experience some wiring fundamentals as they physically wire up the 4 modules plus the CAN bus and supply power and ground. They will also learn how the mul- tiplexed wiring of the 4 modules allows them to communicate on the CAN high speed bus in the same manner as most vehicles vehicle produced since 2008. The wiring diagrams help carry the student from concept to function. All of the lab activities refer back to the supplied wiring diagrams. Additionally all circuits are protected by fuses wired in series with the loads. Some parallel circuits are double protected with a fuse in the series section of the circuit and additional fuses in each parallel section. Students wiring up the trainer will experience circuits as they are frequently are found in vehicles. This makes for an easier transition from the trainer to a vehicle. The language is easily changed directly from the display. If the student cannot see the engine temperature, push the left button on the display panel until engine temperature shows. The instrument cluster, with scan data availability allows for an immediate, live display with multiple line capability. Stu- dents can change an input, such as coolant temperature, and see the change on the display. The display can be in what- ever language the student speaks. This is especially helpful for the ESL (English as a second language) student learning the trade language. The language is easily changed directly from the display. The trainer is especially useful for demonstrations of inputs, outputs and CAN bus signals when the signals are connect- ed to a projector for the class to see. The supplied power supply makes the trainer very portable requiring only a wall outlet to function. The casters on the bottom of the rack make storage, when not in use, easy to accomplish. The train- ers power supply is internally protected against wiring errors including short circuits and accidental grounding of power circuits. NOTE- whenever the trainer is moved from one location to another, it is recommended that each of the fault box but- tons be “cycled” with the programming key “ON” to the 3 o’clock position. Simply push each fault button in and release. The blue light on the button should be it. Then, push the fault button again until the blue light goes off. Then, position the programming key back to the 12 o’clock position. Because the fault box contains mechanical latching relays, moving the trainer can accidentally “trip” the relay and install a fault, but the blue light will not turn on. Cycling each button as described above will eliminate possible confusion. consulab.com info@consulab.com 8 91-MP-1918-2 General Information General Information All circuit and component wiring for both power and grounds, must be made to the front surfaces of the Moduponent™ panels. The wiring located behind the Moduponent™ panels is strictly for fault insertion. The top panel has six red recep- tacles for fuses F1-F6 on the right-hand side. The left-hand side has six black ground receptacles and each is connected together with each other from behind the panel. Students must make all positive and ground circuit connections to these receptacles for the top panel. There are six 10A ATC fuses located just above the BATTERY lamp on the MP-1918-01 panel and five 5A ATC fuses located below the output control module on the MP-1918-02 panel. Each fuse has one receptacle (load side). All circuits should be fused during installation. All circuit connections are made by using the red and black jumper wires that plug into the receptacles located at each component. The jumper wires can be “piggybacked” onto each other by stacking the banana plugs. This feature allows the connecting of many wires at one connection point. NOTE- Do not stack more than three jumper wires on the same connector. ATC Fuses MP-1918-1 GND Receptacles consulab.com info@consulab.com 9 91-MP-1918-2 General Information Connecting the power supply to the Moduponent™ panels Before the MP-1918-02 (middle panel) is mounted to the frame, notice that there is a black two wire terminal block mounted inside on one side of the frame. A black and a red wire is attached to the terminal block using friction tabs which are also connected to the power supply. A flat tip screwdriver of the proper size is used to push in on each fric- tion tab to either insert or remove a wire. Locate the red and black wires coming from the back side of the middle panel and properly connect them to the terminal block. Release tabs PUSH IN Push to release and attach When the middle panel’s red and black wires are properly connected to the power supply terminal block and when the power supply is turned on, the RED power indicator light on the middle panel should illuminate. NOTE : Confirm that the trainer’s power cord is plugged into a receptacle. NOTE : It is normal for the power indicator light to stay on for a few seconds after power supply is switched off. The power supply on this trainer is internally protected from direct short circuits. The power supply is equipped with an ammeter and voltmeter. Meters will display system voltage and amperage as trainer is used. In the event of an acciden- tal direct short circuit, the ammeter display will increase to about 25-35 A and the voltmeter will display approximately 3 V. Although the power supply will sustain a short circuit condition, the circuit wires may feel warm to the touch. If power supply meters display above readings, immediately switch the rocker switch to the OFF position and correct the short circuit. There will be a separate power supply for each side of a double-sided trainer (if equipped). WARNING- The power supply should NEVER be used as a battery charger due to potential serious component damage and the voiding of the warranty. The power supply is specifically designed ONLY to supply a DC power source for our trainers. consulab.com info@consulab.com 10 91-MP-1918-2 Theory Theory consulab.com info@consulab.com 11 91-MP-1918-2 The Theory and Operation of CAN The Theory and Operation of CAN Before we get into the lab activities, it will be helpful to review how a CAN system operates. Most of the systems that are on the road today are similar in style and function, which makes this discussion relevant to just about all vehicles and the MP-1918. CAN stands for Controller Area Network. It is a way for different electronic parts in a vehicle to talk to each other using just two wires. Instead of running a separate wire for every signal, CAN sends many signals over the same wires. This makes the system simpler, reduces the amount of wiring, and helps make the vehicle lighter and easier to maintain.. Think about a common sensor like a TPS (throttle position sensor). There are many vehicle components that need to know the position of the throttle, so the data from the one sensor is sent along a CAN network, where all systems that need the data have access to it. Think of it as a mini-social network. When someone posts something on a social net- work feed, all friends can see the post even if they do not need to know the information. In a similar fashion, the TPS in- formation sent out along the CAN network allows for all modules to have access to it. The connection between modules is done on the CAN bus. A bus is a shared set of wires that lets different parts of a system send and receive information, often wired as a twisted pair to reduce electrical noise. In a CAN bus, there are two wires: CAN HI and CAN LO. They work together as a pair to send data. When a message is sent, the voltage on CAN HI goes up slightly (around 3.5V), and the voltage on CAN LO goes down slightly (around 1.5V). When no message is sent, both wires sit at about 2.5V. Using two wires like this helps cancel out electrical noise and makes communication more reliable. You will easily be able to see both of these signals when they are captured with a DSO (Digital Storage Oscilloscope). consulab.com info@consulab.com 12 91-MP-1918-2 The Theory and Operation of CAN The illustration on the previous page shows how a simple vehicle system similar to the MP-1918 would be configured to control the back-up lights, the brake lights, the marker lights and the turn signal lights in a conventional (non CAN bus) wiring style. Notice that individual wires connect the lights directly to control switches. The below illustration shows the same components wired through a CAN bus. The switch sends an input into the Input Module rather than directly to the component. The CAN bus handles a packet of information including whether the light is to be on or off along the twisted pair of wires (yellow and green). The signal goes to the output module where it is used to turn on or off the light(s). Notice that both modules have their own fused battery positive connection and grounds. Every module in use on the modern vehicle or the MP-1918 needs to have its own power and ground available. The bus is the interconnection between as many modules as the vehicle has. The figure above is a great example of a simplified approach to understanding how CAN will function. Prior to CAN, control circuits contained switches or relays. When you wanted to turn on something you would close a switch and power would run through the load. Usually the load was directly connected to ground, and the battery side of the circuit was switched. When the five example circuits become multiplexed, the battery or switch side of the circuit becomes a series of inputs to an input module. A CAN sig- nal is sent along the CAN bus to the output module. The output module then controls the various loads. Now at first glance, this appears to be more complicated, but does offer some benefits. One benefit is the reduction in the weight of the vehicle by eliminating all the wires between various circuits. For example if an output module can be placed in the rear of the vehicle then all the wires from the front of the vehicle to the rear are eliminated. Power and ground run to the output module along with the CAN bus. If the output module has ten items that it is controlling, ten sets of wires are eliminated, thus saving weight. consulab.com info@consulab.com 13 91-MP-1918-2 The Theory and Operation of CAN If you were to look at a 2012 GMC Terrain, you would see that the CAN bus has seventeen modules connected together. Again, it is like saying that the vehicle has seventeen friends communicating together on social media. There are also components connected to the CAN bus that do not show on this computer data lines circuit. The TPS would be an ex- ample of a component connected to the CAN bus but not a module. Sensors will put their data on the CAN bus so that modules can use it as an input that they need. The Body Control Module, the Engine Control Module, the Cruise Control Module and the Transmission Control Module might all want the data from the TPS, but the Seat Memory Module probably does not need this data, but because it is also on the CAN bus, it will “see” the data. Again, if we reference a social feed with seventeen people online, not every- one wants or needs to know what one friend is doing but all of them can see the post because they are all connected to the network. The CAN bus on the MP-1918 has four modules interconnected by yellow and green wires. The yellow and green wires form the CAN bus network that connects all modules together. End-of-line resistors, also called termination resistors, are placed at both ends of the CAN bus. They connect CAN HI and CAN LO together through a resistor, which helps stop signal reflections and keeps communication stable. Both sides of a high speed CAN bus carry the same information and will be mirror images of each other when viewed with a DSO. Frequently CAN data will appear as bursts of information that are called packets. Each module on the network is pro- grammed to either look at or ignore various pieces or packets of information. When we look at the signal with a DSO (Digital Storage Oscilloscope) we will be able to see that there is data flowing along the CAN bus. consulab.com info@consulab.com 14 91-MP-1918-2 The Theory and Operation of CAN WAKE UP SIGNAL: What is the WAKE UP Signal? When you approach a vehicle that has been off for an extended period of time, the various modules are asleep, drawing virtually no current. It would not make much sense to have the many modules drawing the battery down while the vehicle owner sleeps for 8 hours. The CAN bus needs to come awake once the owner does something. The MP-1918 can demonstrate the concept of wake up easily. Turn on the power supply. Notice that the Input Module, the Engine Control Module and the power light come on. A good exemple of a wake up device on a vehicle would be the key fob. Pushing the UNLOCK button on the fob will wake up the CAN bus system and it will be ready to start functioning. So when this simulated vehicle is resting, or asleep, these two modules are still drawing a very small amount of current. Close the brake switch and notice that the output module lights up, the brake lights go on and after a short amount of time the instrument cluster turns on. The entire trainer woke up because you closed the brake switch. Now the brake lights are drawing current as they should, but only after the input module saw the brake light switch close. The Input Module sent a signal along the CAN bus to the Output Module to wake up and turn on the brake lights. The brake switch has acted as the “wake up signal”. If you open the brake switch, the brake lights go off immediately but the Output Mod- ule and the instrument cluster light will remain on for about 5 sec. They remain on waiting for another input to send data along the CAN bus. If no data appears the CAN bus shuts down or goes to sleep. This is an extremely efficient method of control since it draws current only when necessary. There are many inputs on a vehicle that will act as a wake up signal. Unlocking the doors, putting the key in the ignition, using the power door locks, putting your foot on the brake pedal, etc. are all examples of input signals. All of these actions created by you will wake up the system and get it ready for activity. But also notice if the system is asleep and you move the Engine Coolant Temperature sensor knob, the system does not wake up. The ECT is a thermistor whose resistance changes with engine coolant temperature changes. The resistance value is changing anytime the temperature changes. If its input were to wake up the system it would never go to sleep. The vehicle manufacture determines which inputs will act as wake up signals. It is done through the software design for the CAN bus. GATEWAY: What is the Gateway? A CAN vehicle may have many different modules but the software within the mod- ules will designate one of them as the gateway. The gateway is the connection between different CAN networks. It also functions as the connection to anything that might be plugged into the DLC (Data Link Connector). When a scanner is plugged into the DLC it will receive data from the gateway and display it. With many modern vehicles that have multiple CAN systems, a gateway is necessary. For instance, the Terrain system schematic, shown below, has a low speed and two high speed systems. 0,5217 in 16 1 GATEWAY The green wires that start at pin 1 of the DLC (upper left of the illustration), go to all of the components and modules that are part of the low speed system. consulab.com info@consulab.com 15 91-MP-1918-2 The Theory and Operation of CAN 6 14 GATEWAY Pins 6 and 14 (the Tan or Tan/Blk wires), go to all of the components within the high speed system. There are actually multiple pages to the high speed diagram. We are only showing one page of the Pins 6 and 14 high speed system. GATEWAY Pins 12 and 13 (D-BU and L-BU) are the pins for the second high speed system. The gateway is the link between the low and both high speed CAN systems. On this vehicle the Body Control Module (BCM) is in both high speed and the low speed system. Therefore, the Body Control Module is the gateway and will serve as the link between all three CAN bus systems. It will also function as the link to our diagnostic equipment. When we connect a scanner to the DLC, the BCM will send out information regarding vehicle operations, diagnostic trouble codes (DTCs), and CAN bus data. If there is only one CAN bus present it is difficult to figure out what module is the gateway. consulab.com info@consulab.com 16 91-MP-1918-2 The Theory and Operation of CAN Why are resistors used on the high speed CAN bus? You will notice on many wiring diagrams that there are two resistors across the two wires of the high speed CAN bus. 120 ohms is the usual value of each of these resistors. Two 120 ohm resistors wired in parallel results in a combined resistance of 60 ohms. These resistors have various names but only one purpose. They may be called data link resistors, termination resistors or end-of-line resistors as the MP-1918 calls them. Whatever the name, the function is the same: they allow the communication signal to be used up or absorbed during normal operation and act as a connection for the two sides. If either or both of the resistors were to not function cor- rectly, it is possible that decisions made by the individual modules would not be correct or be missed completely. There is a simple test to verify the integrity of these resistors. This is a good time to look at how we should connect to the DLC on a real vehicle. DLC pins are designed to be connect- ed to specific connectors such as a scanner. Probing the DLC with DMM or DSO probes might damage the pins. For this reason, a DLC Break Out Box (BOB) should be used. Break Out Box (BOB) The BOB allows a connection to all of the 16 pins of the DLC, a connection to a scanner and also gives a visual indication of data. It will protect the DLC. The MP-1918 has open pins that allow connection to the DLC or the Deutch connector without the need to use a BOB. The easiest method to use when testing the resistors is to disconnect the battery or power supply from the CAN net- work by removing the negative battery connection from either the vehicle or the MP-1918. Once this is done connect a DMM across the two pins of the high speed network. Remember that only the high speed 2 wire CAN bus will have resistors. Ohm’s Law states that the total resistance of two equal resistors wired in parallel will be half each value. So the combined resistance of two 120 Ω resistors will be 60 Ω (ohms). Ford HI CAN bus Resistance This illustration shows the resistance on a Ford high speed CAN bus. It shows 61 Ω. Anything relatively close to the 60 Ω value is considered to be good. consulab.com info@consulab.com 17 91-MP-1918-2 The Theory and Operation of CAN What does a functioning CAN bus look like on a Digital Multi Meter (DMM) or a Digital Storage Oscilloscope (DSO)? A CAN bus signal is a series of very fast pulsing voltage signals with variable pulse width. It is the varying width of the signals and not the voltage level changes that contain the communication packet. The packets will come across the CAN bus in extremely quick succession. A DMM will just average the voltage and display a steady voltage reading. This is why a DSO is the preferred tool and one that you will use in the MP-1918 learning activities. The pattern shown above is the CAN Low signal from the MP-1918. Notice that the small pattern box in the lower right of the screen shows a red trace with 5 verticle lines. Each line is a packet of information. The small box around the middle packet is expanded and shows in the center of the screen. It is called CAN Low because the voltage trace starts around 2.5 V and goes down to about 1.0 V. This is one packet of information on CAN Low. CAN Low should not be confused with low speed CAN. With multiple CAN bus circuits on the vehicle you may find one low speed CAN and many high speed CAN. Each high speed CAN is composed of a CAN Low and a CAN High signal that are mirror images of one another. Here is the CAN High trace taken from the MP-1918. consulab.com info@consulab.com 18 91-MP-1918-2 The Theory and Operation of CAN Notice that the signal runs from a low of 2.5 V and goes to a high of about 4.0 V. Again the voltage is not that important and various manufactures will use different voltages. Remember that this is a packet of all the information that is on the high speed CAN bus and it is being transmitted at very high speeds. It will contain all of the sensor inputs, running pa- rameters, and outputs. As vehicle manufactures add modules, the network slows down so they eventually get to a point where they add another CAN bus. Usually the newly added CAN bus will be a high speed CAN with CAN HI and CAN LO signals. If we look at both CAN HI and CAN LO on a dual trace oscilloscope we can see the mirror image. The red trace is CAN Low and the blue trace is CAN High. The small box in the lower left corner shows that three packets of information is available on screen. A small portion is expanded and fills the majority of the DSO screen. The patterns are mirror images of themselves. This allows both sides of the CAN bus to carry the same information. If one side, say CAN LO, were to drop out, the vehicle could still function although not as well. The end of line resistors connect the CAN HI and the CAN LO wires together. They are the reason why the signals are mirror images. A dual trace (2 channel) DSO is required for a technician to “see” what is going on with the high speed CAN bus. Remember the discussion of the WAKE UP signal? We said that it is a signal coming from a sensor indicating that the vehicle CAN bus needs to begin transmitting information. The gateway will now send out the WAKE UP signal on the bus. If we expand the time on screen, called the time base, of the DSO and set it to capture the WAKE UP signal, we should then be able to see that after the system wakes up, packets of information will begin to flow. consulab.com info@consulab.com 19 91-MP-1918-2 The Theory and Operation of CAN Wake Up Signal Signal Packet This figure shows the WAKE UP signal on the left and after a short period of time a packet of information is seen. The wake up signal arrives at all the modules and they first report in, if they are online and indicate within the packet what their condition is. The packet on the right is the reporting in of all modules. In the case of the MP-1918, the four modules are waking up and reporting in. They are beginning to function at this point of the trace and the red communication light comes on. In a vehicle there will not be red lights for each module and instead you will have to connect a scanner to determine the condition of the module. If a module does not wake up, it cannot and will not function. Let’s switch gears a bit away from the MP-1918 and look at some signals from an actual vehicle. You will see that there are only slight variations from the MP-1918. This should allow you to easily transition from the trainer to an actual vehi- cle. Let’s wake up a vehicle: The illustration below shows the WAKE UP signal and then the packets of information on the low speed system. Many vehicles will wake up the CAN system with an input into the low speed system. Wake up signal Signal Packet consulab.com info@consulab.com 20 91-MP-1918-2 The Theory and Operation of CAN Notice the ~10 V pulse on the left side of the trace? This is the WAKE UP signal coming from the gateway. After a short period of time, the packets of information appear. The first packet contains the reports from all the modules indicating that they are online and if they contain any DTC’s (Diagnostic Trouble Codes). The CAN bus is alive and functioning. CAN Low Signal CAN High Signal If we look at the high speed system, we see that the CAN HI and CAN LO signals appear to be mirror images of them- selves, as they should be. Low Speed CAN High Speed CAN HI High Speed CAN LO BAT GND GND The pins are numbered with the top row being one through eight. One is on the left. Pin one is the low speed connection on this vehicle. At the opposite corner of the connector (bottom right) is pin 16. Pin 16 is the power pin and has B+ bat- tery positive on at all times. Pins 4 and 5 are both grounds. consulab.com info@consulab.com 21 91-MP-1918-2 The Theory and Operation of CAN A typical pin-out chart for a vehicle with multiple high speed systems and one low speed system looks like this. Pin Wire Circuit Function 1 0.35 D-GN 5060 Low speed GMLAN Serial Data 2-3 - - Not Used 4 0.35 BK 1550 Ground 5 0.35 BK/WH 1551 Ground 6 0.35 TN/BK 2500 High Speed GMLAN Serial Data bus + 7-11 - - Not Used 12 0.35 DK-BU 6105 High Speed GMLAN Serial Data + 13 0.35 L-BU 6106 High Speed GMLAN Serial Data - 14 0.35 TN 2501 High Speed GMLAN Serial Data bus - 15 - - Not Used 16 0.35 RD/WH 40 Battery Positive Voltage Notice that the Low Speed connection is pin 1. Pins 6 and 14 are the CAN bus for one of the high speed systems, and pins 12 and 13 are for the other high speed system. Both high speed systems have the mirror image low and high signals that we have seen earlier. consulab.com info@consulab.com 22 91-MP-1918-2 The Theory and Operation of CAN On an actual vehicle, if we connect our scanner directly to the DLC, the system will go through a module test that will reveal just how many modules are present and communicating on the CAN bus. Autoenginuity™ is type of a computer-based scan tool and is used for this example. The scan tool pings the modules with the ignition key on and reports that there are a total of 28 modules. Here is the first part of the scan : consulab.com info@consulab.com 23 91-MP-1918-2 The Theory and Operation of CAN And here is the second part : consulab.com info@consulab.com 24 91-MP-1918-2 The Theory and Operation of CAN The next thing to do is check the wiring diagram looking for a total of 28 modules. The number from the wiring diagram must match the scanned number of pinged and awake modules. Here is an example of a simplier vehicle with fewer modules using a hand held scan tool. “Requesting module status” is when the CAN system is sent a wake up call. Once the modules wake up and come online, they will report their status and the screen will change to : This screen states that there are 8 modules awake with none of them having a DTC. Next, we go and compare the list to the communications wiring diagram (shown below) to see if the two match. The wiring diagram for this vehicle shows 8 modules. 1 4 5 16 consulab.com info@consulab.com 25 91-MP-1918-2 The Theory and Operation of CAN So, this low speed system is capable of functioning within its design limits. Next we switch over to the high speed system and again request module status with the following results : This high speed system has 5 modules: one with a DTC. Back to the wiring diagram to see how many modules are sup- posed to be on line. 14 6 All 5 modules are present so this system passes, although we have to investigate the DTC that is present. The process of teaching or diagnosing a CAN bus system involves the following in order: 1. Connect a DMM set to measure ohms across the high speed terminals inside the DLC break out box with the battery disconnected. You should have 60 Ω. 2. Make sure that power and ground are available in the DLC. B+ power pin 16 and grounds are pins 4 and 5. 3. Connect a DSO to the low speed system and capture the WAKE UP signal and at least one packet. NOTE: The MP- 1918 uses the wake up signal on the high speed system. 4. Connect a DSO to the high speed system looking for both high and low signals that are mirror images. 5. Use a scan tool and ping the modules, making sure they are all present and communicating. consulab.com info@consulab.com 26 91-MP-1918-2 Student CAN bus Theory Test Student CAN bus Theory Test Answer Key consulab.com info@consulab.com 27 91-MP-1918-2 Student CAN bus Theory Test Student CAN bus Theory Test 1. CAN allows many modules to... A. share data B. send information to other modules C. control inputs and outputs between various modules D. all of the above 2. Technician A states that the WAKE UP signal is sent out by the Body Control Module. Technician B states that a packet of information will contain information on inputs and outputs. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 3. The CAN bus is down. Technician A states that the vehicle will likely not start. Technician B states that the vehicle will likely not communicate with a scanner. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 4. A vehicle has a CAN bus system that is functioning correctly. The system will have... A. a twisted pair of wires that runs around the entire vehicle B. a fused single wire that will run from the Body Control Module to the dashboard C. a relay center that will communicate with a scanner D. no connection to the DLC 5. Two technicians are discussing the end-of-line resistors. Technician A states that only vehicles produced in the Unit- ed States use them. Technician B states that they are sometimes called termination resistors. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B consulab.com info@consulab.com 28 91-MP-1918-2 Student CAN bus Theory Test 6. Technician A states that a packet of information will precede the WAKE UP signal. Technician B states that the pack- et will contain information about DTCs (diagnostic trouble codes) Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A or Technician B 7. What generates the WAKE UP signal ? A. Body Control Module B. Engine Control Module C. Input Module D. The gateway 8. A scanner is connected to the DLC/Deutsch connector. Technician A states that the scanner will communicate to and from the gateway. Technician B states that the scanner will communicate to and from the Output Module. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A or Technician B 9. A vehicle has a single low speed system and a single high speed system. The wiring diagram shows one module in both systems. This module is the... A. Engine Control Module B. Gateway C. Input Module D. Output Module 10. The DSO shows a mirror image set of signals off of pins 6 and 14 of the DLC. This is the... A. low speed pattern B. wake up pattern C. gateway pattern D. high speed pattern consulab.com info@consulab.com 29 91-MP-1918-2 Student CAN bus Theory Test 11. Two technicians are discussing placing an ohmmeter between pins 6 and 14 of the DLC with the vehicle battery disconnected. Technician A states that an acceptable reading is around 60 Ω. Technician B states that this test is looking at the CAN bus wiring and the end-of-line resistors. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A or Technician B 12. Technician A states that a scanner doing a module status test is actually asking for all the modules to report in. Technician B states that the number of modules reporting in must match the wiring diagram. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A or Technician B consulab.com info@consulab.com 30 91-MP-1918-2 Student CAN bus Theory Test Student CAN bus Theory Test Answer Key 1. D 2. B 3. C 4. A 5. B 6. B 7. D 8. A 9. B 10. D 11. C 12. C consulab.com info@consulab.com 31 91-MP-1918-2 Student Assignements Student Assignments Answers consulab.com info@consulab.com 32 91-MP-1918-2 SA-1 — Wiring the MP-1918 Ground Circuits SA-1 — Wiring the MP-1918 Ground Circuits Objective: I can wire the ground circuits of the MP-1918 and verify their resistance values. Component Specifications Turn signals < 350 mV hazard lights > 3.86 V right turn signal 715 mV - 1.2 V left turn signal 1.3 V - 3.8 V no turn signal Engine Coolant Temperature ( ECT ) 0.0 V - 13.7 V Accelerator pedal 4 V - 13.7 V NOTE: As you build each circuit during the assignments, be sure to draw black (ground) and red (positive) lines showing the wires that you have connected. Introduction: Before we carry on any discussion of multiplex and CAN bus, we need to completely wire up the trainer. It is a bit of all or nothing since the trainer will function correctly only after it is completely and correctly wired. We will look at individual circuits once everything is functional. For this lab the power supply should be OFF. 1. Jumper additional negative (black) wires to all negative load connections. There are 9 negative connections that must all have a black wire connected back to the power supply. NOTE: Remember that all of the supplied wires have open backs that allow wires to be piggy backed. You will have to double up some connections since the main negative terminal strip has six open spots. Start by wiring the six open terminals to the closest three loads. NOTE: A load has resistance and will produce light, heat, and/or magnetic field when current flows through it. Our load panel has lights as the loads. Once the three closest loads have a negative or ground connection, jumper to the next closest load and so on until all nine loads have a ground connection. The three MP-1918 panels should all be connected together at the ground bus. Make sure the power supply is OFF and unplugged from AC power. consulab.com info@consulab.com 33 91-MP-1918-2 SA-1 — Wiring the MP-1918 Ground Circuits SA-1 — Wiring the MP-1918 Ground Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 34 91-MP-1918-2 SA-1 — Wiring the MP-1918 Ground Circuits Instructor Answer Key 2. Prove that all the grounds are good by using an ohmmeter between each load negative and the power supply negative. Record the resistance in the nine spaces below. Use the answer sheet for all your answers. Load 1 to B - 0 Ω Load 4 to B - 0 Ω Load 7 to B - 0 Ω Load 2 to B - 0 Ω Load 5 to B - 0 Ω Load 8 to B - 0 Ω Load 3 to B - 0 Ω Load 6 to B - 0 Ω Load 9 to B - 0 Ω 3. What should a good ohmmeter reading be ? A good ohmmeter reading should be 0 Ω 4. Why should it be 0 Ω? There should not be any resistance in the ground circuits consulab.com info@consulab.com 35 91-MP-1918-2 SA-2 — Testing the MP-1918 Load Circuits SA-2 — Testing the MP-1918 Load Circuits Objective: I can test that all loads and grounds are functional. NOTE: As you build each circuit during the assignment, be sure to draw black (ground) and red (positive) lines showing the wires that you have on the diagram. NOTE: For any load to function, it must also have a positive (red) connection. Because we will be building circuits, we need to include a protection device. The Instrument Cluster Module contains a series of ten fuses. 1. Each of the six fuses on the top 01 Moduponent™ panel will have fused battery voltage available anytime the trainer power is turned ON and the red power indicator light is turned on. If any fuse does not provide battery power, test the fuse for an open condition and replace if needed. 2. Connect a red wire to the F1 fuse connection. Connect the other end to the first load at the top right of the Modu- ponent™ panel, and turn on the power supply. The light should turn on. If not check your connections. For the load to function you need to have a good positive connection and a good negative connection. Check all loads on the load panel in a similar manner. All loads should be functional. If they are not, trace the entire circuit making sure that both positive and negative is available at the load. Remember all nine loads need to be functional. 3. In a similiar manner, test each of the nine load lights on the bottom 03 panel. Does each load light up ? Discussion: In our first circuit the load is the light bulb and it is the only resistance that should be in the circuit. The 10 A fuse will protect the circuit wiring and controls, if there are any. As we tested each load we did not have a control, like a switch, in the circuit. Once we have determined that all loads are functional, we will use each one of these fuses for a different circuit. Many vehicles use a combination lamp for both tail and turn signals. consulab.com info@consulab.com 36 91-MP-1918-2 SA-2 — Testing the MP-1918 Load Circuits SA-2 — Testing the MP-1918 Load Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 37 91-MP-1918-2 SA-2 — Testing the MP-1918 Load Circuits Instructor Answer Key 3. Does each load light work ? Yes X No consulab.com info@consulab.com 38 91-MP-1918-2 SA-3 — Wiring the MP-1918 Remaining Ground Circuits SA-3 — Wiring the MP-1918 Remaining Ground Circuits Objective: I can wire all the remaining ground circuits on the MP-1918 and check that each panel is connected correctly. NOTE: As you build each circuit during the assignments, be sure to draw black (ground) and red (positive) lines showing the wires that you have connected. 1. Jumper a black wire from the 03 Moduponent™ panel up to the 02 Moduponent™ panel (the one with the CAN bus) GND connector on the left side. 2. Now, use a black jumper and connect the GND connector to the 01 Moduponent™ panel. This brings ground to all three panels. 3. On the 01 panel there are 6 grounds. Connect each ground to the GND connection points on the left side of the panel. The last ground connections are on the 02 panel. There are four ground connections to make. Look over the panel: with the exception of some open GND connections on the left edge of the 01 and 02 panels all GND connec- tions should have a black wire connected. 4. All Moduponent™ panels should now be completely wired with black wires connected to each of the modules, switches, and all loads. Also, the 03 and 02 Moduponent™ panels should be ground connected to the 01 Modupo- nent™ panel. Confirm that your trainer matches this description. consulab.com info@consulab.com 39 91-MP-1918-2 SA-3 — Wiring the MP-1918 Remaining Ground Circuits SA-3 — Wiring the MP-1918 Remaining Ground Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 40 91-MP-1918-2 SA-4 — Wiring the MP-1918 Module Circuits SA-4 — Wiring the MP-1918 Module Circuits Objective : I can establish the positive power connections for all four CAN bus modules and the communication inter- face. At this point you should have no connections to the green, yellow or blue sockets. These will be wired later or come into play during future lab activities. As we connect the circuits, keep the power supply OFF. There should not be any po- tential current flowing and the power supply being off ensures this. This is a great idea to firmly plant in your day to day activities. It is not a good idea to connect or disconnect a circuit with current flowing. A voltage spike can occur during connection or disconnection and the spike may damage a sensitive electronic module. 1. As you complete each step, update the diagram by drawing black lines for ground and red lines for positive connec- tions to show the wires you have installed. 2. Connect a red wire from F1 to the BAT terminal of the Display Module. 3. Connect a red wire from F2 to the BAT terminal of the Input Module. NOTE: You are allowing all of these modules to function. For them to do their job they must have both power and ground and be connected to the CAN bus. The power connections that we are currently connecting are the power for the module to function. The modules should have a ground already connected from the previous assignments. 4. Connect a red wire from F3 to the BAT terminal of the Engine Control Module. 5. Connect a red wire from F4 to the BAT terminal of the Output Module. 6. Connect a red wire from F5 to the BAT terminal of the communications connection. NOTE: There are two choices here but only one connection. Connect a red wire between F5 and the BAT terminal of the combination Deutsch/ DLC connection. Both of these connectors will have power and ground normally available. Most scanners will pow- er up off of the BAT and the GND terminals in either connector. The Deutsch connector is normally found on heavy duty applications and the DLC on automotive applications. 7. Have your instructor sign below once the module power connections are complete. 8. Be sure to draw in the red lines on the SA-4 answer sheet as you make power connections to the trainer. consulab.com info@consulab.com 41 91-MP-1918-2 SA-4 — Wiring the MP-1918 Module Circuits SA-4 — Wiring the MP-1918 Module Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 42 91-MP-1918-2 SA-5 — Wiring the MP-1918 Input Circuits SA-5 — Wiring the MP-1918 Input Circuits Objective : I can wire inputs to the Engine Control Module. NOTE: Our last major fuse is F6. It will be used for multiple input power. You will have to piggy back the connectors forming a parallel circuit. 1. As you complete each step, update the diagram by drawing black lines for ground and red lines for positive connec- tions to show the wires you have installed. 2. Connect a red wire between F6 and the backup switch. 3. Jumper from the backup switch to the headlamp switch. NOTE: Jumpering and forming a parallel circuit is easy with the wires supplied with the MP-1918. Each wire has an open back that will allow a connection to another component. 4. Connect a red wire between F6 and the BAT terminal of the turn signal switch. 5. Jumper from the turn signal switch and the WAKE UP switch, the ECT (Engine Coolant Temperature), and the accel- erator pedal assembly. NOTE: These are some of the inputs to the engine module. This concludes the wiring of the modules. When it is completed, show your instructor. consulab.com info@consulab.com 43 91-MP-1918-2 SA-5 — Wiring the MP-1918 Input Circuits SA-5 — Wiring the MP-1918 Input Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 44 91-MP-1918-2 SA-6 — Wiring the MP-1918 B+ Load Circuits SA-6 — Wiring the MP-1918 B+ Load Circuits Objective : I can wire the B+ loads on the 03 Moduponent™ panel. NOTE: The last positive wiring that needs to be accomplished is the direct wiring of the BAT terminal of each of the loads. 1. As you complete each circuit, update the diagram by drawing black lines for ground and red lines for positive con- nections to show the wires you have installed. 2. Connect a red wire between F7 and the P (Park lamp) terminal of the right and left tail lamp assembly. 3. Connect a red wire between F8 and one of the five marker lamps (The lamps on the top of the 03 panel). 4. Jumper all of the marker lamps and the license lamp together. NOTE: The marker lights should all be parallel together at the lights. 5. Connect a red wire between F9 and the backup light. 6. Connect a red wire between F10 and the left turn/stop (TS/S). 7. Connect a red wire between F11 and the right turn/stop lamp. 8. Be sure to draw in the red lines on the SA-6 answer sheet as you make power connections to the trainer. This completes the wiring of the loads. Have your instructor check your work before moving onto the CAN bus wiring. consulab.com info@consulab.com 45 91-MP-1918-2 SA-6 — Wiring the MP-1918 B+ Load Circuits SA-6 — Wiring the MP-1918 B+ Load Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 46 91-MP-1918-2 SA-7 — Wiring the MP-1918 CAN bus Communication Circuits SA-7 — Wiring the MP-1918 CAN bus Communication Circuits Objective : To wire the communications bus between the 4 modules and the combination DLC/Deutsch connector. Note : prior to wiring the CAN bus, turn the power on. 1. As you complete each circuit, update the diagram by drawing black lines for ground and red lines for positive con- nections to show the wires you have installed. 2. What happened – be specific. What lights are on? 3. What lights are off? 4. Close the turn signal switch. Does the turn signal lamp light? 5. Why doesn’t the turn signal lamp light? 6. Note : The module are in control of the lights and must need something else to be function. There has to be com- munication to “tell” them to turn on and begin functioning. The CAN bus is used as the communication connection. All modules must communicate to all modules whether they be on the input or output side of the circuit. Also remember that CAN stands for Controller Area Network. When you network with someone you communicate with them whether it be face to face or via social media. Think of the CAN Network as the social media connection in the vehicle. If you post something on Facebook, all of your friends that are networked with you can see the post. CAN functions the same. When the brake switch is closed, all networked modules can see it. Only certain modules will respond to it, but everyone can see it. The CAN bus is a parallel connection between modules. The green and yellow wires are the CAN bus on the MP 1918 and their connections are really easy to accomplish. Connect all module yellow connections to the CAN bus connector Block. You should now have 4 sets of yellow/ green wires at the block. There are three open connections left. One set will go to the combination Deutsch/DLC connections. The remaining two will each go to a 120 ohm resistor sometimes referred to as the end of line resistor or termination resistors. These 2 – 120 ohm resistors serve no easily seen function. They are responsible for the communication side of a high speed CAN bus. Communication errors can result if for some reason these connec- tions are not functioning correctly. The diagram below shows a block style communications wiring diagram for the MP-1918. When working on a CAN bus system on a vehicle, the first step should be to print a communications wiring diagram that shows the connection to the DLC (Data Link Connector) under the dash. Frequently our diagnosis will involve the DLC or in the case of a heavy duty vehicle, the Deutsch connector. consulab.com info@consulab.com 47 91-MP-1918-2 SA-7 — Wiring the MP-1918 CAN bus Communication Circuits The trainer is now fully wired. At this point show it to your instructor, who will check it prior to powering it up. consulab.com info@consulab.com 48 91-MP-1918-2 SA-7 — Wiring the MP-1918 CAN bus Communication Circuits SA-7 — Wiring the MP-1918 CAN bus Communication Circuits Wiring Diagram Answer Key GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG consulab.com info@consulab.com 49 91-MP-1918-2 SA-7 — Wiring the MP-1918 CAN bus Communication Circuits Instructor Answer Key 1. What lights are on ? Only the module status lights 2. What lights are off ? All load lights are off 3. Does the turn signal lamp light ? No 4. Why doesn’t the turn signal lamp light ? No power from the output module consulab.com info@consulab.com 50 91-MP-1918-2 SA-8 — Basic CAN bus Function SA-8 — Basic CAN bus Function Objective : I can perform basic diagnostic tests on a CAN Bus network to verify communication integrity and correct resistance values using Ohm’s Law principles. A CAN bus network sends packets of information along the bus (the yellow and green wires). The packets contain all the input and output information that is required by all modules to function. The first test usually done on a CAN bus is designed to test the ability of the network to communicate. 1. Turn OFF the power supply. 2. Connect the meter test leads from a digital multimeter (DMM) together. 3. Turn on the DMM to the ohms position and record your resistance. Ω NOTE: You are testing the meter’s connection. 4. What should the meter read ? Ω 5. Why should the meter read the answer in question 4 ? 6. With the DMM still on ohms, connect the meter leads into the CAN bus connections at the DLC. Meter polarity does not matter. 7. Record your reading here. Ω NOTE: Refer back to the MP-1918 CAN bus communications wiring diagram. 8. How many resistors are there in the diagram ? 9. What value does each resistor have in ohms ? Ω 10. Use the principles of Ohm’s Law and explain how the two resistors equal the value in question 7. NOTE: When you do a resistance check of the circuit you are testing its integrity. Without the correct resistance val- ue, the modules on the network cannot communicate effectively. Communication DTCs (Diagnostic Trouble Codes) may result if the resistance value is incorrect. 11. Disconnect one lead on either resistor. 12. What does the ohmmeter now read ? Ω 13. What is the significance of this reading ? consulab.com info@consulab.com 51 91-MP-1918-2 SA-8 — Basic CAN bus Function SA-8 — Basic CAN bus Function Instructor Answer Key 3. Record your reading here : 0 Ω 4. Record your reading here : 0 Ω 5. Why should the meter read the answer in question 4 ? There should be no resistance between the DMM leads 7. Record your reading here: 60 Ω 8. How many resistors are there in the diagram ? 2 9. What value does each resistor have in ohms? 120 Ω 10. Use the principles of ohms law and explain how the two resistors equal the value in question 7. The total resistance of a circuit with two equal resistances is equal to ½ the resistance of each resistance. 12. Record your reading here : 120 Ω 13. What is the significance of this reading ? It shows the actual resistance value of the resistor, not total circuit resis- tance. consulab.com info@consulab.com 52 91-MP-1918-2 SA-9 — MP-1918 Viewing a CAN Low Packet of Information SA-9 — MP-1918 Viewing a CAN Low Packet of Information Objective : I can analyze CAN bus low communication packets, including voltage and packet duration, using a Digital Storage Oscilloscope (DSO). A CAN bus system communicates in bursts of information called packets. This extremely fast, short bursts of informa- tion is easily viewed using a DSO. 1. Set up a single channel DSO to view a signal between 0.0 V and 10 V. NOTE: Turn off trigger so that you see a solid line at 0.0 V with no connection to the MP-1918. 2. Turn on the MP-1918 and the WAKE UP switch. This will allow the modules to begin communicating. You should see the four module lights on. 3. Connect the ground wire of the DSO to the GND connection of the DLC. 4. Connect the input connector of the DSO to the LOW (green) connector. 5. You should see a burst of changing voltage floating across the screen. 6. Hold the pattern on the screen. NOTE: you might have to use trigger to lock a pattern on the screen. 7. Measure the highest voltage achieved and record it. V 8. Measure the lowest voltage achieved and record it. V 9. How long does the packet last ? ms (milliseconds) 10. If a printer is available, print a copy of the DSO pattern or show your instructor. consulab.com info@consulab.com 53 91-MP-1918-2 SA-9 — MP-1918 Viewing a CAN Low Packet of Information SA-9 — MP-1918 Viewing a CAN Low Packet of Information Instructor Answer Key 7. Record your reading here: 3.0 V 8. Record your reading here: 1.0 V 9. How long does the packet last? 2.0 ms (milliseconds) consulab.com info@consulab.com 54 91-MP-1918-2 SA-10 — MP-1918 Viewing a CAN High Packet of Information SA-10 — MP-1918 Viewing a CAN High Packet of Information Objective : I can analyze CAN bus high communication packets, including voltage levels and packet duration, using a Digital Storage Oscilloscope (DSO). CAN high and CAN low work together to transmit data, but their voltage levels differ. CAN High rises above the midpoint during communication, while CAN Low drops below it. This differential signaling ensures reliable data transfer and noise immunity. 1. Set up a single channel DSO to view a signal between 0.0 V and 10 V. NOTE: Turn off trigger so that you see a solid line at 0.0 V with no connection to the MP-1918. 2. Turn on the MP-1918 and the WAKE UP switch. This will allow the modules to begin communicating. You should see the four module lights on. 3. Connect the ground wire of the DSO to the GND connection of the DLC. 4. Connect the input connector of the DSO to the HIGH (yellow) connector. 5. You should see a burst of changing voltage floating across the screen. 6. Hold the pattern on the screen. NOTE: you might have to use trigger to lock a pattern on the screen. 7. Measure the highest voltage achieved and record it. V 8. Measure the lowest voltage achieved and record it. V 9. How long does the packet last? ms (milliseconds) 10. If a printer is available, print a copy of the DSO pattern or show your instructor. consulab.com info@consulab.com 55 91-MP-1918-2 SA-10 — MP-1918 Viewing a CAN High Packet of Information SA-10 — MP-1918 Viewing a CAN High Packet of Information Instructor Answer Key 7. Record your reading here: 4.0 V 8. Record your reading here: 2.0 V 9. How long does the packet last? 2.0 ms (milliseconds) consulab.com info@consulab.com 56 91-MP-1918-2 SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel DSO SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel DSO Objective : I can compare packet timing and voltage between CAN High and CAN Low using a two-channel Digital Stor- age Oscilloscope (DSO). A two-channel Digital Storage Oscilloscope (DSO) [bold “two-channel Digitiscal Storage Oscilloscope (DSO)”] allows you to view two signals at the same time, one on each channel. This is beneficial for CAN Bus diagnostics because you can observe CAN High and CAN Low simultaneously, making it easier to compare voltage levels and packet timing. Seeing both patterns together helps confirm proper differential signaling and network integrity. 1. Set up a two-channel DSO to view a signal between 0.0 V and 10 V. NOTE : Turn off trigger so that you see two solid lines at 0.0 V with no connection to the MP-1918. 2. Turn on the MP-1918 and the WAKE UP switch. This will allow the modules to begin communicating. You should see the four module lights on. 3. Connect the ground wire of the DSO to the GND connection of the DLC. 4. Connect the input connector of the DSO channel 1 (channel A) to the Low (green) connector. 5. Connect the input connector of the DSO channel 2 (channel B) to the High (yellow). 6. You should see a burst of changing voltage floating across the screen. 7. Hold the pattern on the screen. NOTE: you might have to use trigger to lock a pattern on the screen. You may find it necessary to move the set points of each channel to view the two patterns clearly. There should be a space between the patterns. 8. What differences or similarities do you notice when viewing CAN High and CAN Low signals together on the same screen? 9. Adjust the time base on the DSO until you have two patterns on the screen. 10. How much time was the packet on for ? ms 11. How much time was there between packets ? ms 12. If a printer is available, print a copy of the DSO pattern or show your instructor. consulab.com info@consulab.com 57 91-MP-1918-2 SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel Channel DSO SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel Channel DSO Instructor Answer Key 8. What differences or similarities do you notice when viewing CAN High and CAN Low signals together on the same screen? The CAN High and CAN Low signals appear as mirror images of each other, with voltage changes starting and stop- ping at the same time. 10. How much time was the packet on for ? 2.0 ms 11. How much time was there between packets ? 6.0 ms consulab.com info@consulab.com 58 91-MP-1918-2 SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO Objective : I can capture and analyze a CAN Bus wake up signal and its communication packet using a two-channel Digi- tal Storage Oscilloscope (DSO). 1. Turn off any input switches including the WAKE UP switch. 2. Wait until the Output Module and the Engine Control Module lights go out. This ensures that the CAN bus system is asleep. 3. Set up a two channel DSO to view a signal between 0.0 V and 10 V. NOTE: Turn off trigger so that you see two solid lines at 0.0 V with no connection to the MP-1918. 4. Turn on the MP-1918 and the WAKE UP switch. 5. Connect the GND wire of the DSO to the GND connection of the DLC. 6. Connect the input connector of the DSO channel 1 (channel A) to the LO (green) connector. 7. Connect the input connector of the DSO channel 2 (channel B) to the HI (yellow). 8. Set the trigger to single. 9. Set the trigger set point to one division from the left. 10. Set the trigger voltage to around 4.0 V with a positive slope. NOTE: if you need help getting trigger set correctly, ask your instructor. It may take several tries to actually cap- ture the wake up signal and packet on the same screen. 11. Set the scope to capture a pattern once the trigger has been satisfied. NOTE: The correct pattern will show the wake up signal and at least one packet of communication. 12. Close the brake switch. The Engine Control Module and the Output Module lights should light and a pattern should be locked onto the DSO screen. NOTE: If only the wake up is present increase the amount of time per division (t/div), turn off the brake switch, wait until the Engine Control Module and the Output Module lights go off, and reset the DSO. Continue trying until the wake up signal and at least one packet of information is present. 13. If a printer is available, print a copy of the DSO pattern or show your instructor. consulab.com info@consulab.com 59 91-MP-1918-2 SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO Answer key consulab.com info@consulab.com 60 91-MP-1918-2 SA-13 — MP-1918 Digital to Analog Control SA-13 — MP-1918 Digital to Analog Control Objective: I can observe and explain how an input sensor signal is processed by a module, transmitted over the CAN bus, and activates an output load using a two-channel DSO. 1. Set up the MP-1918 so that everything functions. 2. Wire the DSO channel one (A) into J2-4 of the Input Module and GND. J2-4 is the input from the backup light switch. NOTE: There are multiple sets of blue connections with the designation of J2-4. Make sure you use the Input Module connections. 3. Wire the DSO channel two (B) into J1-10 of the Output Module, which is the power to the backup lamp. 4. Set a single trace trigger off of channel two in the right side of the screen at about 5.0 V with a positive slope. NOTE: Remember that a positive slope means that the trigger conditions will be met when the voltage is rising and passes 5.0 V. 5. Make sure the power supply is ON and close the backup light switch. 6. What happened ? 7. Why did this occur ? 8. Open the backup switch and close the WAKE UP switch. NOTE: The CAN bus should wake up. 9. Close the backup switch. 10. What happened ? 11. Why did this occur ? 12. If a printer is available, print a copy of the DSO pattern or show your instructor. consulab.com info@consulab.com 61 91-MP-1918-2 SA-13 — MP-1918 Digital to Analog Control SA-13 — MP-1918 Digital to Analog Control Instructor Answer Key 6. What happened ? Nothing 7. Why did this occur ? It is not an input that will wake up the CAN bus. 10. What happened ? Channel 1 went from 0-12 V and after a slight delay channel 2 also went from 0 to 12 V. 11. Why did this occur? The backup switch sent 12 V to the Input Module, which relayed it via the CAN bus to the Output Module which turned on the light. consulab.com info@consulab.com 62 91-MP-1918-2 SA-14 — MP-1918 Input Module Inputs SA-14 — MP-1918 Input Module Inputs Objective : During this lab, you will use the wiring diagram to identify the input module blue test points and record the voltages to the input module with the switches in different positions. Note: After testing place the switch back in the off position. 1. Correctly wire all circuits on the MP-1918 and confirm that everything functions correctly. 2. With the WAKE UP switch up, all four modules should have the status lights ON. 3. Leave the WAKE UP switch in the ON position. (up). 4. Obtain the Input Module wiring diagram. Identify the blue J test receptacles that match up with the following input switches : A. Backup Switch J B. Hazard Switch J C. Brake Switch J D. Headlamp Switch Low J Park J 5. Record the voltage at the correct J test receptacle with the switch OFF and ON. Backup Switch OFF Volts ON Volts 6. Record the voltage at the correct J test receptacle with the switch OFF and ON. Hazard Switch OFF Volts ON Volts 7. Record the voltage at the correct J test receptacle with the switch OFF and ON. Brake Switch OFF Volts ON Volts 8. Record the voltage at the correct J test receptacle with the switch OFF and ON. both LOW and PARK. Headlamp switch OFF Volts On Low Volts On Park Volts 9. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system? 10. Be prepared to discuss your results with your instructor. consulab.com info@consulab.com 63 91-MP-1918-2 SA-14 — MP-1918 Input Module Inputs SA-14 — MP-1918 Input Module Inputs Instructor Answer Key 4. Obtain the Input Module wiring diagram. Identify the blue J test receptacles that match up with the following input switches: A. Backup Switch J 2-4 B. Hazard Switch J 1-5 C. Brake Switch J 1-4 D. Headlamp Switch Low J 1-6 ( Low ) Park J 1-7 ( Park ) 5. Record the voltage at the correct J test receptacle with the switch OFF and ON. Back-up Switch OFF 4.0 Volts ON 13.7 Volts 6. Record the voltage at the correct J test receptacle with the switch OFF and ON. Hazard Switch OFF 4.0 Volts ON 0.0 Volts 7. Record the voltage at the correct J test receptacle with the switch OFF and ON. Brake Switch OFF 4.0 Volts ON 0.0 Volts 8. Record the voltage at the correct J test receptacle with the switch OFF and On both low and park. Headlamp switch OFF 0.02 Volts On Low 13.5 Volts On Park 13.6 Volts 9. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system? The different voltages act as inputs to the module. The module “looks” at the voltage differences and changes the state of the load. consulab.com info@consulab.com 64 91-MP-1918-2 SA-15 — MP-1918 CAN Cluster Module inputs SA-15 — MP-1918 CAN Cluster Module inputs Objective : I can identify Cluster Module test points using a wiring diagram and measure voltage changes at each input to explain how these voltages control system functions. 1. Correctly wire all circuits on the MP-1918 and confirm that everything functions correctly. 2. With the WAKE UP switch up, all four modules should have the red status lights ON. 3. Leave the WAKE UP switch in the “ON” position. (up). 4. Obtain the Cluster Module wiring diagram. Identify the blue J test receptacles that match up with the following input switches. A. Engine Brake Switch J B. Turn Signal Switch J 5. Record the voltage at the correct J test receptacles with the switch OFF and ON. Remember to turn the switch back ON after performing each test. Engine Brake Switch OFF Volts ON Volts 6. Record the voltage at the correct J test receptacles with the switch OFF and ON for both the right and left turn signals. Turn Signal Switch OFF Volts ON Right Volts ON Left Volts 7. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system ? 8. Be prepared to discuss your results with your instructor. consulab.com info@consulab.com 65 91-MP-1918-2 SA-15 — MP-1918 CAN Cluster Module inputs SA-15 — MP-1918 CAN Cluster Module inputs Instructor Answer Key 4. Obtain the Cluster Module wiring diagram. Identify the blue J test receptacles that match up with the following input switches. A. Engine Brake Switch J 1-5 B. Turn Signal Switch J 1-4 5. Record the voltage at the correct J test receptacles with the switch OFF and ON. Engine Brake Switch OFF 4.0 Volts ON 0.0 Volts 6. Record the voltage at the correct J test receptacles with the switch OFF and ON for both the right and left turn signals. Turn Signal Switch OFF 2.0 Volts ON Right 5.8 Volts ON Left 0.0 Volts 7. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system ? The different voltages act as inputs to the module. The module “looks” at the voltage differences and changes the state of the load. consulab.com info@consulab.com 66 91-MP-1918-2 SA-16 — MP-1918 ECM Inputs SA-16 — MP-1918 ECM Inputs Objective: I can identify ECM test points using a wiring diagram and measure voltage changes from switches and sensors in different positions to explain how these voltages control system operation. 1. Correctly wire all circuits on the MP-1918 and confirm that everything functions correctly. 2. With the WAKE UP switch up, all four modules should have the red status lights ON. 3. Leave the WAKE UP switch in the ON position (up). 4. Obtain the ECM wiring diagram. Identify the blue J test receptacles that match up with the following input switch or sensor: A. ECT Sensor J B. Idle Validation Switch J C. Pedal Position Sensor J D. WAKE UP Switch J 5. Record the voltage at the correct J test receptacles with the switch OFF and ON. Idle Validation Switch OFF Volts ON Volts 6. Record the voltage from the ECT sensor at the following positions. Full OFF position Volts Full ON Position Volts ½ position Volts 7. Record the voltage from the Pedal Position Sensor at the following positions. Full OFF position Volts Full ON Position Volts ½ position Volts 8. Record the voltage at the correct J test receptacles for the WAKE UP switch. WAKE UP OFF (down) Volts WAKE UP ON (up) Volts 9. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system? 10. Be prepared to discuss your results with your instructor. consulab.com info@consulab.com 67 91-MP-1918-2 SA-16 — MP-1918 ECM Inputs SA-16 — MP-1918 ECM Inputs Instructor Answer Key 4. Obtain the ECM wiring diagram. Identify the blue J test receptacles that match up with the following input switch or sensor : A. ECT Sensor J 1-7 B. Idle Validation Switch J 1-4 C. Pedal Position Sensor J 1-6 D. WAKE UP Switch J 2-4 5. Record the voltage at the correct J test receptacles with the switch OFF and ON. Idle Validation Switch OFF 4 Volts ON 0 Volts 6. Record the voltage from the ECT sensor at the following positions. Full OFF position 0.02 Volts Full ON Position 13.6 Volts ½ position 5.6 Volts 7. Record the voltage from the Pedal Position Sensor at the following positions. Full OFF position 4 Volts Full ON Position 13.6 Volts ½ position 6.8 Volts 8. Record the voltage at the correct J test receptacles for the WAKE UP switch. WAKE UP OFF (down) 4 Volts WAKE UP ON (up) 13.6 Volts 9. Explain the purpose of the different voltages that you have measured. How does the module use these voltages to operate the system? The different voltages act as inputs to the module. The module “looks” at the voltage differences and changes the state of the load. consulab.com info@consulab.com 68 91-MP-1918-2 SA-17 — MP-1918 Engine Control Module Inputs — Part 1 SA-17 — MP-1918 Engine Control Module Inputs — Part 1 Objective : I can measure and interpret the idle validation switch input to the Engine Control Module using a voltmeter to explain how the ECM detects idle position and communicates this status through the CAN bus. 1. Ensure that the MP-1918 is fully functional. 2. Switch the WAKE UP signal ON. All four modules should have their status lights ON. 3. Place a voltmeter into Engine Control Module break out pin (blue) J1-4. Use the module GND pin for the ground con- nection. With the switch OFF (down), what does the voltmeter read? V 4. Close the Idle Validation switch. 5. What does the instrument cluster show ? 6. What does the voltmeter read ? V 7. Does the MP-1918 indicate in any other manner that idle position has occurred ? 8. How does the Engine Control Module recognize that the Idle Validation switch is in a closed position ? 9. How does the Idle Validation switch function? Indicate the sequence involving specific modules and the CAN bus. consulab.com info@consulab.com 69 91-MP-1918-2 SA-17 — MP-1918 Engine Control Module Inputs — Part 1 SA-17 — MP-1918 Engine Control Module Inputs — Part 1 Instructor Answer Key 3. Place a voltmeter into Engine Control Module break out pin (blue) J1-4. Use the module GND pin for the ground con- nection. With the switch OFF (down), what does the voltmeter read? 4.0 V 5. What does the instrument cluster show ? Pedal switch ON 6. What does the voltmeter read ? 0.0 V 7. Does the MP-1918 indicate in any other manner that idle position has occurred ? Yes, the MP-1918 indicates idle position by showing that engine speed drops. 8. How does the Engine Control Module recognize that the Idle Validation switch is in a closed position ? The Engine Control Module recognizes the closed position because it applies a ground signal (0.0 V). 9. How does the Idle Validation switch function? Indicate the sequence involving specific modules and the CAN bus. The idle validation switch functions by applying a ground to the ECM input, which then communicates through the CAN bus to the instrument cluster to change the display. consulab.com info@consulab.com 70 91-MP-1918-2 SA-18 — MP-1918 Engine Control Module Inputs — Part 2 SA-18 — MP-1918 Engine Control Module Inputs — Part 2 Objective: I can measure the Accelerator Pedal Position Sensor input to the Engine Control Module using a voltmeter to analyze how pedal position influences system behavior and communication. 1. Ensure that the MP-1918 is fully functional. 2. Switch the WAKE UP signal ON. All four modules should have their status lights ON. 3. Place a voltmeter into Engine Control Module break out pin (blue) J1-6. Use the module GND pin for the ground con- nection. Rotate the Pedal Position sensor while observing the voltmeter. 4. With the sensor in the fully counter clockwise position, what does the voltmeter read ? V. What does the instrument cluster read ? . 5. With the sensor in the fully clockwise position, what does the voltmeter read ? V. What does the instrument cluster read ? . 6. With the sensor in the middle position, what does the voltmeter read ? V. What does the instrument cluster read ? . 7. Does the MP-1918 indicate in any other manner that pedal position has changed ? 8. Close the Idle Validation switch. Move the Pedal Position sensor. 9. What does the Engine Control Module do when the Idle Validation switch is in a closed position and the Pedal Posi- tion sensor is moved ? 10. Indicate the sequence and modules in use during the Pedal Position sensor movement and the Idle Validation switch position changes. consulab.com info@consulab.com 71 91-MP-1918-2 SA-18 — MP-1918 Engine Control Module Inputs — Part 2 SA-18 — MP-1918 Engine Control Module Inputs — Part 2 Instructor Answer Key 4. With the sensor in the fully counter clockwise position, what does the voltmeter read ? 4.0 V. What does the instrument cluster read ? Closed Throttle ( 0% ) . 5. With the sensor in the fully clockwise position, what does the voltmeter read ? 13.7 V. What does the instrument cluster read ? Wide Open Throttle ( 99-100% ) . 6. With the sensor in the middle position, what does the voltmeter read ? 6.0 V. What does the instrument cluster read ? 24% 7. Does the MP-1918 indicate in any other manner that pedal position has changed ? Speed changes on display 9. What does the Engine Control Module do when the Idle Validation switch is in a closed position and the Pedal Position sensor is moved ? Keeps engine at idle 10. Indicate the sequence and modules in use during the Pedal Position sensor movement and the Idle Validation switch position changes. Pedal Position Sensor sends a variable voltage signal to the ECM along CAN bus to Instrument Cluster for display. The idle validation switch overrides the Pedal Position Sensor. consulab.com info@consulab.com 72 91-MP-1918-2 SA-19 — MP-1918 Engine Control Module Inputs — Part 3 SA-19 — MP-1918 Engine Control Module Inputs — Part 3 Objective : I can interpret the Engine Coolant Temperature (ECT) sensor input to the Engine Control Module using a volt- meter to analyze how temperature changes affect system readings and module communication. 1. Ensure that the MP-1918 is fully functional. 2. Switch the WAKE UP signal ON. All four modules should have their status lights ON. 3. Place a voltmeter into Engine Control Module break out pin (blue) J1-7. Use the module GND pin for the ground con- nection. Rotate the ECT sensor while observing the voltmeter. 4. With the sensor in the fully counter clockwise position, what does the voltmeter read ? V. What does the instrument cluster read ? 5. With the sensor in the fully clockwise position, what does the voltmeter read ? V. What does the instrument cluster read ? 6. With the sensor in the middle position, what does the voltmeter read ? V. What does the instrument cluster read ? 7. Does the MP-1918 indicate in any other manner that ECT has changed ? 8. Indicate the sequence and modules in use during the ECT sensor changes. consulab.com info@consulab.com 73 91-MP-1918-2 SA-19 — MP-1918 Engine Control Module Inputs — Part 3 SA-19 — MP-1918 Engine Control Module Inputs — Part 3 Instructor Answer Key 4. With the sensor in the fully counter clockwise position, what does the voltmeter read ? 0.0 V. What does the instrument cluster read ? -40 degrees 5. With the sensor in the fully clockwise position, what does the voltmeter read ? 13.7 V. What does the instrument cluster read ? 392 degrees 6. With the sensor in the middle position, what does the voltmeter read ? 5.5 V. What does the instrument cluster read ? 140 degrees 7. Does the MP-1918 indicate in any other manner that ECT has changed ? Instrument Cluster displays temperature of the engine 8. Indicate the sequence and modules in use during the ECT sensor changes. ECT sends variable voltage to ECM through CAN bus to Instrument Cluster for display of engine temperature. consulab.com info@consulab.com 74 91-MP-1918-2 SA-20 — MP-1918 CAN bus Activity SA-20 — MP-1918 CAN bus Activity Objective: I can monitor and evaluate CAN bus packet activity using a Digital Storage Oscilloscope (DSO) to determine how system actions and sensor changes affect communication patterns. 1. Ensure that the MP-1918 is fully functional. 2. Switch the WAKE UP signal ON. All four modules should have their status lights ON. 3. Connect a DSO into the CAN bus. NOTE: you can use CAN High, CAN Low or both. You will be looking for changes in activity. 4. Use trigger, slope and position to get a pattern on the screen. Set trigger so that one packet pattern is displayed. Expand the pattern so it fills the screen. NOTE: Some DSO will show this as repeat. Your DSO should show a single packet that repeats continuously across the screen. 5. Once the pattern is repeating and locked on, close a switch (any switch) and watch for the packet of information. 6. Did the packet show changes ? 7. Rotate the Pedal position Sensor or the ECT sensor with all other switches in the OFF position (with the exception of the WAKE UP switch) 8. Did the packet show changes ? 9. What does this indicate? consulab.com info@consulab.com 75 91-MP-1918-2 SA-20 — MP-1918 CAN bus Activity SA-20 — MP-1918 CAN bus Activity Instructor Answer Key 6. Did the packet show changes ? Yes X No 8. Did the packet show changes ? Yes X No 9. What does this indicate ? Very slight instantaneous change consulab.com info@consulab.com 76 91-MP-1918-2 Student Assessment Student Assessment Answer Key consulab.com info@consulab.com 77 91-MP-1918-2 Student Assessment Student Assessment 1. What should the resistance of the ground path on a functioning CAN bus system be ? A. 60 Ω B. 120 Ω C. Infinity D. 0.0 Ω 2. Which of the following inputs can act as the wake up signal ? A. Backup switch B. Turn signal switch C. Brake switch D. Engine Coolant Temperature (ECT) 3. The CAN bus circuit connects... A. all modules together with the DLC/Deutsch connector B. only the input module to the output module C. the controlled loads to the ground path D. the fuses to the modules 4. The resistance of the CAN bus is being measured. Technician A states that the battery should be disconnected. Technician B states that the ohmmeter should be placed between pins 6 and 14 of the DLC. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 5. The end-of-line resistors are being measured. The correct value should be... A. 120 Ω B. 60 Ω C. 0.0 Ω D. Infinity Ω consulab.com info@consulab.com 78 91-MP-1918-2 Student Assessment 6. A CAN Low signal is observed on a DSO. Technician A states that the voltage signal will start high and be pulled down. Technician B states that the voltage signal will start low and be pulled up. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 7. The CAN High and CAN Low signal is observed on a DSO. A correctly functioning system will have... A. only a low or a high signal B. signals that alternative, first high, then low. C. a wake up signal after a packet D. mirror images of the information packet 8. Technician A states that the wake up signal only occurs once a day. Technician B states that the wake up signal precedes a packet of information. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 9. A vehicle is turned off and has all doors closed with the key NOT in the ignition. Technician A states that unlocking the door will wake up the system. Technician B states that the system is awake now. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 10. Engine temperature changes. Technician A states that the change will go out over the CAN bus to all modules. Tech- nician B states that the change will wake up the CAN bus. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 11. Turning on the brake lights results in a slight delay between closing the switch and having the lights go on. A. This indicates a problem in the end-of-line resistors B. This is normal C. This will result in a DTC being set D. None of the above consulab.com info@consulab.com 79 91-MP-1918-2 Student Assessment 12. Refer to the below pattern. It is... A. only a CAN Low signal B. only a wake up signal C. only a CAN High signal D. both a wake up signal and a CAN packet 13. A Throttle Position Sensor send a... A. pulsing CAN signal B. variable voltage signal C. ON-OFF signal D. switched B+ signal 14. Technician A states that a scanner connected to a DLC will display information off of the CAN bus. Technician B states that a scanner can be used to display DTCs. Who is correct ? A. Technician A only B. Technician B only C. Both Technician A and Technician B D. Neither Technician A nor Technician B 15. A scanner requests module status. It shows 6 modules online. This indicates... A. the CAN bus is up and functioning B. the wake up signal should be the next thing to happen C. the CAN bus is offline D. none of the above consulab.com info@consulab.com 80 91-MP-1918-2 Student Assessment Instructor Answer Key 1. D 2. C 3. A 4. C 5. B 6. A 7. D 8. B 9. A 10. A 11. B 12. D 13. B 14. C 15. A consulab.com info@consulab.com 81 91-MP-1918-2_V2024-1 MP-1918 Wiring Template GND TS/SGND P 4321 765 TS/SGND P HV-1918-03_052926 REVG MP-1918 Wiring Template Circuit : consulab.com info@consulab.com 82 91-MP-1918-2 Instrument Cluster Module Schematic Instrument Cluster Module Schematic With Faults 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 FO LIO 1/5 D ESSIN E : VER IFIE : D ATE D E C R EATIO N : IN D IC E D ATE M O D IFIC ATIO N D ES. Logiciel SEE 3.70 v. C A N LO C LU STER J1-1 J1-2 J1-4 J2-1 J2-2 J1-3 V B A T V B A T TU R N SIG . C A N H I C A N LO G N D J1-1 J1-2 J1-4 J2-1 J2-2 J1-3 C A N H I J1-5 EN G B R A K E J1-5 J1-9 D ISPLA Y TU R N SIG N A L SW ITC H EN G IN E B R A K E Initial release FS 1.00 M A RTIN SIRO IS M U LTIPLEX TRA IN ER M P-1918-1 C A N D ISPLA Y 2301-M 2 12 4 3 V B A T C A N H I G N D R ELA Y C A N LO A N LG .IN PU T 65 N CN O C O M 17-04-2025 consulab.com info@consulab.com 83 91-MP-1918-2 Input Module Schematic Input Module Schematic With Faults 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 FO LIO 2/5 D E S S IN E : V E R IFIE : D A TE D E C R E A TIO N : IN D IC E D A TE M O D IFIC A TIO N D E S . Logiciel S E E 3.70 v. IN PU T M O D U LE J1-1 J1-2 J1-3 J1-4 J1-5 J1-6 V B A T V B A T G N D B R A K E H A ZA R D J2-1 J2-2 J2-4 C A N H I C A N LO B A C K -U P J1-7 H EA D LA M P B A C K -U P H A ZA R D B R A K E H .L. LO W H .L. PA R K LO W PA R K J1-1 J1-2 J1-3 J1-4 J1-5 J1-6 J2-1 J2-2 J2-4 J1-7 C A N LO C A N H I Initial release FS 1.00 M A R TIN SIR O IS M U LTIPLEX TR A IN ER M P-1918-1 17-04-2025 consulab.com info@consulab.com 84 91-MP-1918-2 Engine Control Module Schematic Engine Control Module Schematic With Faults EN G IN E M O D U LE J1-1 J1-2 J1-3 J1-4 J1-6 V B A T V B A T G N D ID LE V A L. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 FO LIO 3/5 D ESSIN E : VER IFIE : D ATE D E C R EATIO N : IN D IC E D ATE M O D IFIC ATIO N D ES. Logiciel SEE 3.70 v. J2-1 J2-2 C A N H I C A N LO J1-7 PED A L PO SITIO N SIG EC T SIG PED A L PO SITIO N SEN SO R ID LE V A LID A TIO N SW ITC H EC T SEN SO R A C C ELER ETO R PED A L A SSEM B LY C A N LO C A N H I J1-1 J1-2 J1-3 J1-4 J1-6 J2-1 J2-2 J1-7 W A K E-U P J2-4 W A K E U P J2-4 Initial release FS 1.00 M A RTIN SIRO IS M U LTIPLEX TRA IN ER M P-1918-1 17-04-2025 consulab.com info@consulab.com 85 91-MP-1918-2 Output Module Schematic Output Module Schematic With Faults 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 FO LIO 4/5 D E S S IN E : V E R IFIE : D A TE D E C R E A TIO N : IN D IC E D A TE M O D IFIC A TIO N D E S . Logiciel S E E 3.70 v. O U TPU T M O D U LE V B A T V B A T G N D C A N H I C A N LO PA R K IN G LA M P B A C K -U P M A R K ER LEFT TU R N / STO P R IG H T TU R N / STO P C O N TR O LLER O U TPU T R ELA Y S J1-1 J1-2 J1-3 J1-8 J2-1 J2-2 J1-9 J1-10 J2-7 J2-8 F7 5A F8 5A F9 5A F11 5A J1-1 J1-2 J1-3 J1-8 J2-1 J2-2 J1-9 J1-10 J2-7 J2-8 C A N LO C A N H I M A R K ER LA M P 5 LIC EN SE LA M P B A C K -U P LA M P PA R K IN G LA M P R IG H T PA R K IN G LA M P LEFT LEFT TU R N / STO P R IG H T TU R N / STO P M A R K ER LA M P 4 M A R K ER LA M P 3 M A R K ER LA M P 2 M A R K ER LA M P 1 F10 5A Initial release FS 1.00 M A R TIN SIR O IS M U LTIPLEX TR A IN ER M P-1918-1 17-04-2025 consulab.com info@consulab.com 86 91-MP-1918-2 CAN bus System Schematic CAN bus System Schematic With Faults 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 FO LIO 5/5 D ESSIN E : VER IFIE : D ATE D E C R EATIO N : IN D IC E D ATE M O D IFIC ATIO N D ES. Logiciel SEE 3.70 v. Initial release FS 1.00 M A RTIN SIRO IS M U LTIPLEX TRA IN ER M P-1918-1 17-04-2025 400-6330 Zéphirin-Paquet St. Québec QC G2C 0M3 Canada © ConsuLab Educatech Inc, 2025. All rights reserved. MP-1918 CAN bus Multiplex Trainer Introduction General Information Connecting the power supply to the Moduponent™ panels The Theory and Operation of CAN Student CAN bus Theory Test Answer Key Student CAN bus Theory Test Student CAN bus Theory Test Answer Key Student Assignments Answers SA-1 — Wiring the MP-1918 Ground Circuits Instructor Answer Key Wiring Diagram Answer Key SA-2 — Testing the MP-1918 Load Circuits Instructors Answer Key Wiring Diagram Answer Key SA-3 — Wiring the MP-1918 Remaining Ground Circuits Wiring Diagram Answer Key SA-4 — Wiring the MP-1918 Module Circuits Wiring Diagram Answer Key SA-5 — Wiring the MP-1918 Input Circuits Wiring Diagram Answer Key SA-6 — Wiring the MP-1918 B+ Load Circuits Wiring Diagram Answer Key SA-7 — Wiring the MP-1918 CAN bus Communication Circuits Instructors Answer Key Wiring Diagram Answer Key SA-8 — Basic CAN bus Function Instructor Answer Key SA-9 — MP-1918 Viewing a CAN Low Packet of Information Instructor Answer Key SA-10 — MP-1918 Viewing a CAN High Packet of Information Instructors Answer Key SA-11 — MP-1918 Viewing a CAN bus Communication Using a Two-Channel DSO Instructor Answer Key SA-12 — MP-1918 Viewing a CAN bus Communication Wake Up Signal Using a Two-Channel Channel DSO Answer key SA-13 — MP-1918 Digital to Analog Control Instructor Answer Key SA-14 — MP-1918 Input Module Inputs Instructor Answer Key SA-15 — MP-1918 CAN Cluster Module inputs Instructor Answer Key SA-16 — MP-1918 ECM Inputs Instructor Answer Key SA-17 — MP-1918 Engine Control Module Inputs — Part 1 Instructor Answer Key SA-18 — MP-1918 Engine Control Module Inputs — Part 2 Instructor Answer Key SA-19 — MP-1918 Engine Control Module Inputs — Part 3 Instructor Answer Key SA-20 — MP-1918 CAN bus Activity Instructor Answer Key Student Assessment Answer Key Student Assessment Instructor Answer Key MP-1918 Wiring Template Instrument Cluster Module Schematic With Faults Input Module Schematic With Faults Engine Control Module Schematic With Faults Output Module Schematic With Faults CAN bus System Schematic With Faults
