797 and 797B Off-Highway Truck Caterpillar

Illustration 1	g00875930
Data link circuit

This diagnostic code is recorded when the chassis ECM reads a diagnostic code that is internal to the brake/cooling ECM.

The possible causes of this diagnostic code are listed:

• The brake/cooling ECM has failed. There are no serviceable parts within the ECM.

Note: Ensure that the CID 0533 FMI 12 is active.

Note: It may be possible to communicate using the ET. If ET will not communicate, then try the WinFlash program. Attempt to reflash the ECM.

System Response:

Information for the Brake ECM is not available over the CAT data link. The machine is limited to the lower gears. See Testing and Adjusting, RENR2677, "Rear Axle Gear Limit Function" for additional information.

Test Step 1. VERIFY THAT THE DIAGNOSTIC CODE IS PRESENT.

1. Turn the key start switch and the disconnect switch to the OFF position.

2. Remove connectors J1 and J2 from the ECM and reconnect connectors J1 and J2 to the ECM.

3. Turn the key start switch and the disconnect switch to the ON position.

4. Clear all inactive diagnostic codes.

5. Operate the machine.

6. Check whether CID 0533 FMI 12 is active.

Expected Result:

The CID 0296 FMI 12 is NOT active.

Results:

• OK - The diagnostic code is NOT present.

  Repair: The initial diagnostic code was probably caused by a poor electrical connection. This could have been a short at one of the harness connectors that was disconnected and then reconnected.

  STOP

• NOT OK - The diagnostic code is present. The ECM may have failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this diagnostic code procedure again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".

  STOP