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| Illustration 1 | g01257797 |
Schematic of the J1939 Data Link | |
The diagnostic trouble code is associated with the Transmission ECU. The FMI 14 means that the ECU is not receiving the proper information from the data link.
Note: Ensure that all of the electronic control units are powered and that the wiring for the J1939 data link is properly connected. This diagnostic trouble code will become active when the Transmission ECU is powered and the Engine ECM is not powered.
The possible causes of this diagnostic trouble code are listed:
- Incompatible software or missing parameters from a message
- Requests of complete parameter are missing.
- Expecting parameters from features that are not enabled
- Problems with the data link during ECU flash programming.
- The incorrect flash program was performed.
- Problems with the data link during downloads of data
- Errors in the data link from other controls on the data link
Note: There can be problems during attempts to download data. The problems can come from an ECU that requests a parameter when a flash program is being attempted. The ECU may only service one of the requests. Problems can occur when an ECU is expecting a parameter from another ECU that does not support the message.
System Response:
The diagnostic trouble code remains active until a power cycle has occurred and the requested parameters have been received.
Note: Changing parameters or configurations might require a power cycle. The power cycle clears diagnostic trouble codes that are caused by missing parameters or incompatible software. This also can be managed in the design of the system. When the parameters are changed, the ECU will request the parameters again. The ECU then clears the diagnostic trouble codes.
Test Step 1. VERIFY SOFTWARE VERSION.
Note: Check and record the latest software version for the machine electronic controls that is available in SIS or on the CD.
- Verify that the Transmission ECU has the correct, most current software.
- Verify that every ECU has the correct, most current software.
Expected Result:
All of the software is up current.
Results:
- OK - All of the software is current.STOP
- NOT OK - The software is not current.
Repair: Flash all controls with the latest software release. Refer to Testing and Adjusting, "Electronic Control Unit - Flash Program". The diagnostic trouble code is no longer active.
STOP
Test Step 2. INSPECT THE HARNESS CONNECTIONS.
- Turn the disconnect switch and the keyswitch to the OFF position.
- Inspect all of the harness connections. Make sure that the connections of the connectors are clean and tight.
- Check the connectors for proper mating. Ensure that all of the seals are present and in place.
- Check the harness for signs of damage or abrasion.
- Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit. Take care not to pull the wire out of the connector.
- Check the exposed portion of the wire at the connector for nicks or signs of abrasion.
- Check for moisture that is inside of the connector.
- Check connectors for dirty contacts or corroded contacts.
- Check each pin and each socket of the machine harness connector. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.
Note: See the Testing and Adjusting, "Electrical Connector - Inspect" section of this manual for more information.
Expected Result:
The machine harness connectors are connected properly. The connectors are free of corrosion.
Results:
- OK - The harness connections are correct. Proceed to Test Step 3.
- NOT OK - The harness connections need repaired.
Repair: Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE ENABLED PARAMETERS FOR THE MACHINE.
- Turn the disconnect switch and the key start switch to the ON position.
- Use the Caterpillar Electronic Technician (ET) in order to view all of the enabled parameters.
Expected Result:
Parameters are enabled for functions that are not available on the transmission.
Results:
- OK - Parameters are enabled for functions that are not available on the transmission.
Repair: Disable the parameters that are not available. Turn the key start switch to the OFF position. Turn the key start switch to the ON position.
Proceed to Test Step 4.
- NOT OK - The parameters that are enabled for the transmission are correct. Proceed to Test Step 4.
Test Step 4. CHECK IF THE DIAGNOSTIC TROUBLE CODE REMAINS.
- Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
- Reconnect all harness connectors. Make sure that the harness connectors are fully seated and that the clips for each connector are fastened completely.
- Turn the disconnect switch and the key start switch to the ON position.
- Operate the vehicle.
- Check the status of the SPN 639 FMI 14.
Expected Result:
The SPN 639 FMI 14 is active.
Results:
- YES - The SPN 639 FMI 14 is active. The diagnostic trouble code has not been corrected.
Repair: Check the circuit again. It is unlikely that the ECU has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic trouble code is not found, replace the ECU. Prior to replacing an ECU, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, "Electronic Control Unit - Replace".
STOP
- NO - The SPN 639 FMI 14 is not active. The diagnostic trouble code does not exist at this time. The initial diagnostic trouble code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal vehicle operation.STOP