950M and 962M Wheel Loaders Caterpillar

CAN Data Link - Test

Usage:

962M EJB

Implement ECM

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

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Table 1
Implement ECM (MID 82)
DTC	Code Description	System Response
247-9	SAE J1939 Data Link: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. (See machine schematic.)
296-9	Transmission Control: Abnormal Update Rate	The Implement ECM will not be able to send/receive proper signal information from the Transmission ECM. Feature functionality may be limited.
296-12	Transmission Control: Bad Device or Component	Implements may not be locked out when the engine is being started.
296-14	Transmission Control: Special Instruction	The Implement ECM has not received all required signal information from the Transmission ECM. Feature functionality may be limited.
590-9	Engine Control Module: Abnormal update rate	The Implement ECM will not be able to send/receive proper signal information from the Engine ECM. Feature functionality may be limited.
590-14	Engine Control Module: Special Instruction	This fault will only occur as a result of the CDL datalink fault.
800-9	VIMS Main Module: Abnormal Update Rate	The Implement ECM will not be able to send/receive proper signal information from the VIMS ECM. Feature functionality may be limited.
800-14	VIMS Main Module: Special Instruction	This fault will only occur as a result of the CDL datalink fault.
1558-9	Electronic Implement Control #2: Abnormal Update Rate	The Implement ECM will not be able to send/receive proper signal information from the RDM ECM. Feature functionality may be limited.
2954-14	Unknown Electronic Implement Control: Special Instruction	Machine components that directly communicate on this link will be unavailable.
3583-9	Switch Panel #1: Abnormal Update Rate	The Implement ECM will not be able to send/receive proper signal information from the Keypad. Feature functionality may be limited.

Possible causes for an FMI 9 Diagnostic code are:

The wrong software is installed on an ECM.
An improper key was used.
The ECM is operating intermittently.
Terminating resistors on the J1939 data link are faulty.
An open or a poor connection in the data link circuit.
Short in the data link circuit.
An ECM or smart device is not powering up or powering down properly.
Lack of key switch input to an ECM or smart device (where applicable).
The energize circuit for the MSS Key Reader may have failed.
Excessive noise on the data link circuit.
One of the ECMs or smart devices has failed. This condition is unlikely.

Possible causes for an FMI 12 Diagnostic code are:

The data link wire has failed.
One of the ECMs are mismatched.

Possible causes for an FMI 14 Diagnostic code are:

A fuse for one of the ECM modules may have failed.
The software is incorrect or incompatible for one of the modules within the data link.
The machine harness has failed.
One of the ECM modules in the data link has failed.

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Illustration 1	g03646569
Schematic of the CAN Data Link circuits

Note: The diagram above is a simplified schematic of the connections for the CAN data link circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 for the complete schematic.

Transmission ECM

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

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Table 2
Transmission ECM (MID 81)
DTC	Code Description	System Response
247-9	SAE J1939 Data Link: Abnormal Update Rate	Machine components that directly communicate on this link will be unavailable. (See machine schematic.)
1960-9	Ignition Key Reader: Abnormal Update Rate	The Transmission ECM will not be able to send/receive proper signal information from the MSS Key Reader ECM. Feature functionality may be limited.
590-9	Engine Control Module: Abnormal Update	The Transmission ECM will not be able to send/receive proper signal information from the Engine ECM. Feature functionality may be limited.
596-9	Implement Control: Abnormal Update Rate	The Transmission ECM will not be able to send/receive proper signal information from the Implement ECM. Feature functionality may be limited.

Possible causes for an FMI 9 Diagnostic code are:

The wrong software is installed on an ECM.
An improper key was used.
The ECM is operating intermittently.
Terminating resistors on the J1939 data link are faulty.
An open or a poor connection in the data link circuit.
Short in the data link circuit.
An ECM or smart device is not powering up or powering down properly.
Lack of key switch input to an ECM or smart device (where applicable).
The energize circuit for the MSS Key Reader may have failed.
Excessive noise on the data link circuit.
One of the ECMs or smart devices has failed. This condition is unlikely.

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Illustration 2	g03646569
Schematic of the CAN Data Link circuits

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.

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Table 3
Troubleshooting Test Steps	Values	Results
1. Identify The Active FMI Code Associated With The CAN Data Link	Code present.	FMI 9, proceed to Test Step 2. FMI 12 , proceed to Test Step 5. FMI 14 , proceed to Test Step 7.
Begin Process For FMI 9 Troubleshooting HERE
2. Check The Data Link For An Open A. Turn the key switch and the battery disconnect switch to the OFF position. B. Disconnect the machine harness connector from the ECM. C. At the disconnected connector for the ECM, connect a jumper wire between CAN positive contact and CAN negative contact. D. Measure the resistance from the ECM.	The resistance measure less than 5 ohms.	OK - The resistance is less than 5 ohms . Proceed to Test Step 3. NOT OK -The resistance measurement is greater than 5 ohms. Repair: Repair or replace the machine harness. Proceed to Test Step 6.
3. Check The Resistance Of The Data Link A. Turn key start switch and disconnect switch OFF. B. Disconnect the machine harness connector from the ECM. C. At the disconnected harness connector of the ECM, measure the resistance between CAN positive contact and CAN negative contact.	The resistance reading is around 60 ohms.	OK - The resistance measurement is approximately 60 ohms. Proceed to Test Step 4. NOT OK - The resistance measurement is not approximately 60 ohms. Repair: Replace the resisters. Proceed to Test Step 6.
4. Check The Data Link For A Short A. Turn key start switch and disconnect switch OFF. B. Disconnect all harnesses from the ECM. C. At the ECM, measure the resistance between CAN positive contact and a ground point. D. Measure the resistance between CAN positive contact and all of the other circuits that are used.	The resistance is greater than 4K ohms.	OK - The resistance is greater than 4K ohms. Proceed to Test Step 6. NOT OK - One or more of the resistance measurements is less than 4K ohms . Repair: Find the short circuit in the data link circuits in order to resolve this problem. Proceed to Test Step 6.
Begin Process For FMI 12 Troubleshooting HERE
5. Verify The Hardware And The Software Part Numbers⁽¹⁾ A. The part number of the flash software for the ECM. B. The part number of the flash software for the "Monitor Display" ECM. 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 6. NOT OK - All of 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. Refer to the Troubleshooting, "ECM Software - Install" section of this manual for additional information. Proceed to Test Step 6.
6. 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 if diagnostic code is active.	Diagnostic code is no longer present.	OK - The diagnostic code is no longer active. Repair: 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 diagnostic code is active. Repair: A failure of the ECM is unlikely. If the cause of the diagnostic code is not found, the ECM may have failed. Prior to replacing an ECM, always contact the Technical Communicator for your dealership for possible consultation with Caterpillar. This consultation may effect repair time. If the ECM requires replacement, see the Troubleshooting, "ECM - Replace" section of this manual for additional information. STOP
Begin Process For FMI 14 Troubleshooting HERE
7. Check The Fuses For The ECM Modules On The CAN Data Link Circuit. A. Turn the key switch and the disconnect switch to the OFF position. B. Refer to the full system schematic to determine if the suspected circuit has an in line fuse. C. If applicable, check the continuity of the fuse related to the active diagnostic code.	The fuse is operational (or intact).	OK- The fuse has not failed. Proceed to Test Step 8. NOT OK- The fuse has failed. Repair: Replace the fuse. STOP
8. Check The Software. A. Use Cat^® Electronic Technician (Cat ET) to verify that the software versions for the data link modules are correct and compatible..	The proper software is installed	OK- The proper software is installed. Proceed to Test Step 9. NOT OK- The proper software is not installed. Repair: Flash the proper software to the appropriate ECM module. Cycle the key start switch to initialize the software. Ensure that the diagnostic code is no longer active. STOP
9. Check For Power To The Key Reader A. Inspect the harness. Clean the harness connector contacts, inspect for corrosion or damage, and inspect the insulation for damage from heat, corrosion, or chafing. B. Perform a 45 N (10 lb) pull test on each circuit wire. C. Reconnect all harness connectors. Verify that the connectors are fully seated and the clips are fastened. D. Use Cat ET to perform a wiggle test on the harness. E. Turn the key switch and disconnect switch ON and operate the machine. F. Check the status of the previously identified diagnostic code.	The previously identified diagnostic code is no longer active.	OK- The diagnostic code is no longer active. Repair: The initial diagnostic code was probably caused by a poor connection at one of the connections that was inspected. Clear the diagnostic code. STOP NOT OK- The diagnostic code remains active. Repair: Ensure that the proper software is installed before replacing the ECM. If the software is correct, replace the ECM.