824H Wheel Dozer, 825H Soil Compactor and 826H Landfill Compactor Electrohydraulic System Caterpillar

Illustration 1	g01157081
Schematic of the Cat Data Link circuit

This diagnostic code is recorded when the implement ECM does not recognize the harness code that is being sent by the Caterpillar monitoring system ECM.

The possible causes of this diagnostic code are listed:

• The wrong software has been installed in the Caterpillar Monitoring System.

• The wrong software has been installed in the implement ECM.

System Response:

This machine response is listed:

• All implements are disabled.

Note: Ensure that the diagnostic code is active.

Test Step 1. VERIFY THE HARDWARE AND THE SOFTWARE PART NUMBERS

1. Verify that the following information is correct:
   • The part number of the flash software for the implement ECM

   • The part number of the implement ECM

   • The part number of the flash software for the Caterpillar monitoring system ECM

   • The part number of the Caterpillar monitoring system ECM

   Note: Consult the dealer for the correct part numbers of the flash software.

Expected Result:

All the part numbers are correct.

Results:

• YES - All the part numbers are correct. Proceed to Test Step 2.

• NO - All the part numbers are NOT correct.

  Repair: Replace the incorrect ECM with a module that has the correct part number. Flash new software into the existing ECM if the ECM part number is correct. See the Testing and Adjusting, "Electronic Control Module (ECM) - Flash Program" section of this manual.

  Stop.

Test Step 2. CHECK FOR ADDITIONAL DIAGNOSTIC CODES FOR THE OTHER ELECTRONIC CONTROL MODULES

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

2. One at a time, reconnect the electronic control modules that use the Cat Data Link.

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

4. After each of the electronic control modules has been reconnected, check the Event List for diagnostic codes that are logged against the electronic control module.

Expected Result:

Diagnostic codes are not present for the other electronic control modules in the event list.

Results:

• YES - Diagnostic codes are not present for the other electronic control modules in the event list.

  Repair: The implement ECM has failed. It is unlikely that the ECM has failed. Exit this procedure. Perform this procedure again. If the failure is not found, check the +battery contacts and ground contacts of the ECM. If these contacts are correct, replace the ECM.

  Stop.

• NO - Diagnostic codes are present for the other electronic control modules (ECM) in the event list.

  Repair: The Caterpillar Monitoring System ECM has failed. It is unlikely that the ECM has failed. Exit this procedure. Perform this procedure again. If the failure is not found, replace the ECM. See the Testing and Adjusting, "Electronic Control Module (ECM) - Replace" section of this manual.

  Stop.