16M3 and 18M3 Motor Graders Information Display Caterpillar

CAN Data Link - Test

Usage:

18M3 E9W

Graphical Display

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the CAN data link of the machine.

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Table 1
Graphical Display (MID 053)
DTC	Code Description	System Response
296-09	Transmission Control: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
590-09	Engine Control Module: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
596-09	Implement Control: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
811-09	Gauge Cluster #1: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
1558-09	Electronic Implement Control #2: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
2348-09	SAE J1939 Data Link #2: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.
2466-09	Engine Aftertreatment Control #1: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. See electrical schematic.

Each CAN data link circuit is an input and output of select electronic control modules. The data link consists of internal control circuits and the connecting harness wiring. The CAN data link is designed to carry communications between the electronic control modules.

Possible Causes for an FMI 09 diagnostic code are:

The wrong software is installed on an ECM.
An improper key was used.
The Graphical Display is operating intermittently.
Terminating resistors on the J1939 data link are faulty.
There is an open or a poor connection in the data link circuit.
There is a short in the data link circuit.
An ECM or smart device is not powering up or powering down properly.
There is a lack of key switch input to an ECM or smart device (where applicable).
There is excessive noise on the data link circuit.
One of the ECMs or smart devices has failed. This condition is unlikely.

Note: A loss of power to an ECM can cause the Graphical Display to activate this diagnostic code combination. Ensure that the ECMs with this diagnostic code are powered up before proceeding with this procedure.

An FMI 09 means that the Graphical Display has lost all communication with another control module.

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Illustration 1	g03874882

Note: The diagram above is a simplified schematic of the Graphical Display connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. For the complete schematic, refer to the latest revision of the machine's Electrical Schematic.

Diagnostic Trouble Code Procedure

Poor connections can often be the cause of a problem in an electrical circuit. Prior to beginning this procedure, perform the following checks:

Inspect the harness connectors that are involved in the circuit.
Verify that all connections in the circuit are clean, secure, and in good condition.
Check the wiring for pinch points or abrasions.
Look for and repair areas that indicate wires are exposed.

If a problem with a connection is found, correct the problem and verify that a diagnostic code is active before performing a troubleshooting procedure.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Identify The Active FMI Code Associated With The CAN Data Link	Code present.	FMI 09, proceed to Test Step 2.
Begin Process For FMI 09 Troubleshooting HERE
2. Verify The Hardware And The Software Part Numbers⁽¹⁾ A. The part number of the flash software for the ECMs on the CAN data link. B. The part number of the flash software for the Graphical Display. C. The part number of all components related to the faulty data link circuit.	All part numbers are correct.	OK - All part numbers are correct. Proceed to Test Step 3. NOT OK - All the part numbers are not correct. Repair: A module has the wrong part number or the incorrect flash software is installed. Replace the incorrect module with a module that has the correct part number. Flash the correct software. See the Testing and Adjusting, "Module - Flash Program" section of this manual for additional information. Proceed to Test Step 10.
3. Inspect The Harness Connections A. Turn the key start switch and disconnect switch OFF. B. Inspect all harness connections related to the CAN data link. Make sure that the connectors are clean and tight. C. Check the connectors for proper mating. Ensure that all the seals are present and in place. D. Check the harness for signs of damage or abrasion. E. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector. F. Check the exposed wires at the connectors for nicks or signs of abrasion. G. Check for moisture inside the connector. H. Check the connectors for dirty contacts or corroded contacts. I. Check each pin and each socket of the machine harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two halves of the connector are placed together.	The machine harness connectors are tight and free of corrosion.	OK - The machine harness connectors are tight and free of corrosion. Proceed to Test Step 4. NOT OK - The machine harness connectors are in need of repair. Repair: Repair or replace the machine harness. Proceed to Test Step 10.
4. Check The Voltage Of The Data Link A. Turn the keyswitch and the disconnect switch to the ON position. B. Connect Cat^® Electronic Technician (Cat ET) Service Tool and verify which ECMs have logged communication diagnostics. At each ECM or device that is not communicating, use an electrical spoon (multimeter probes) to measure the voltage. One at a time, measure the voltage of the CAN data link wires to frame ground.	The reading is 0.5 V to 4.5 V on each wire.	OK - The voltages of the wires for the data links are correct. Proceed to Test Step 7. NOT OK - The voltage is greater than 4.5 V. Proceed to Test Step 8. NOT OK - The voltage is less than 0.5 V. Proceed to Test Step 5.
5. Check For Short To Ground In the Data Link A. The key start switch and disconnect switch remain OFF. B. Disconnect the machine harness connectors from all electronic control modules that use the suspect CAN data link. C. At the machine harness for the Graphical Display, measure the resistance between frame ground and the positive CAN connector contact of the circuit. D. At the machine harness for the Graphical Display, measure the resistance between frame ground and the negative CAN connector contact of the circuit.	The reading is greater than 5K Ω.	OK - The harness circuit resistance is correct. Proceed to Test Step 6. NOT OK - A reading is less than 5 Ω. The machine harness has failed. Repair: There is a short between frame ground and the contacts of the CAN data link circuit in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 10.
6. Check For A Short Between The Data Link Wires A. The keyswitch and the disconnect switch remain in the OFF position. B. Disconnect the terminating resistors if the resistors are a part of the circuit. C. Measure the continuity between the data link wires.	The reading is greater than 5K Ω.	OK - The resistance measurement is correct. Proceed to Test Step 7. NOT OK - The resistance measurement is not correct. The wires for the data link are shorted together. Repair: Repair the machine harness or replace the harness. Proceed to Test Step 10.
7. Check The Terminating Resistors A. The keyswitch and the disconnect switch remain in the OFF position. B. The terminating resistors remain disconnected. C. Check the terminating resistor connectors for the following: -Moisture -Corrosion -Damaged Terminals -Loose Connections D. Measure the resistance between terminal A and B of each terminating resistor that was removed from the CAN circuit.	The reading is approximately 120 Ω.	OK - Both resistance measurements are approximately 120 Ω. The terminating resistors have not failed. Reinstall the terminating resistors. Proceed to Test Step 8. NOT OK - One or both resistance measurements are not approximately 120 Ω. At least one of the resistors is not functioning properly. Replace the terminating resistor or resistors that have failed. Reinstall the terminating resistor that has not failed. Proceed to Test Step 10.
8. Check For A Short To +Battery Circuit In The Data Link A. The key start switch and disconnect switch are OFF. B. All related modules remain disconnected from the machine harness. C. At the machine harness connector for the Graphical Display, measure the resistance between the connector contact for the +Battery and the positive CAN connector contact. D. At the machine harness connector for the Graphical Display, measure the resistance between the connector contact for the +Battery and the negative CAN connector contact.	The reading is greater than 5K Ω.	OK - The harness circuit resistance is correct. Proceed to Test Step 9. NOT OK - A reading is less than 5 Ω. The machine harness has failed. Repair: There is a short between the +battery circuit and one of the CAN data link circuits in the machine harness. Repair or replace the machine harness. Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit. Proceed to Test Step 10.
9. Check The Data Link For An Open Note: Two 120 Ω resistors should be located on the CAN data link. A resistance of 60 Ω should be found at any point on the data link. A. The key start switch and disconnect switch are OFF. B. Use an electrical spoon to connect to the back of the harness connector for each ECM that has communication issues. C. Measure the resistance across the CAN line at each connector to find the open wire. If the resistance measurement is 60 Ω, that connector does not have an open between either terminating resistor. If the resistance measurement is 120 Ω, there is an open at that connector between one of the terminating resistors. If the resistance is greater than 5000 Ω, there is an open between that connector and both terminating resistors. If there is a measurement of 40 Ω, there is an extra terminating resistor somewhere on the line. Once the section of harness containing the open is isolated, repair or replace the machine harness.	All resistance measurements are between 55 and 65 Ω.	OK - The resistance measurements are correct. Proceed to Step 10. NOT OK - At least one resistance measurement is greater than 65 Ω. If the resistance is approximately 115 to 125 Ω. There is an open in the harness. Repair: Repair or replace the machine harness. Proceed to Test Step 10. NOT OK - At least one resistance measurement is less than 55 Ω. Repair: Look for the source of the short by disconnecting the terminating resistors and check the resistance again. If the resistance is still under 55 Ω, continue disconnecting ECMs and devices from the CAN circuit until the resistance goes up. If everything is disconnected from the CAN circuit and the resistance is still less than 55 Ω, the harness has failed. Repair or replace the machine harness. Proceed to Test Step 10.
10. Check If The Diagnostic Code Remains A. Inspect the contacts of the harness connectors and clean the contacts. B. Reconnect all harness connectors. C. Turn the disconnect switch and the key start switch to the ON position. D. Operate the machine. E. Check the status of the DTC.	The DTC is no longer active.	OK - The DTC is no longer active. The initial diagnostic code could have been caused by a poor electrical connection or a short at one of the harness connectors. Resume normal machine operation. STOP. NOT OK - The DTC diagnostic code is active. Repair: A failure of the Graphical Display is unlikely. If the cause of the diagnostic code is not found, the Graphical Display or an ECM may have failed. Prior to replacing a Graphical Display or an ECM, always contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may affect repair time. STOP.