CX28 Transmission For Combat and Tactical Vehicles Transmission ; Transfer Case Electronic Control System Caterpillar

Prior to the replacement of the ECU, ensure that replacement is necessary. The ECU is seldom the cause of a failure. Always check that power is available to all of the contacts of the ECU that are marked with "+ Battery".

Note: Corrupted configuration software or the wrong software may cause an ECU to incorrectly report diagnostic trouble codes. Prior to replacing the ECU, flash the ECU with the correct configuration software in order to verify that the failure is not related to corrupted software. See Testing and Adjusting, "Electronic Control Unit - Flash Program".

Procedure

1. Connect the Caterpillar Electronic Technician (Cat ET). Note all configurations.

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

3. Disconnect the machine harness connectors from the ECU.

4. Verify that the part number of the replacement ECU is correct.

5. Install the replacement ECU.

6. Connect the machine harness to the ECU.

7. Turn the disconnect switch and the key start switches to the ON position.

8. Check for correct configurations. If necessary, use the Cat ET to install the configuration software. Refer to the Testing and Adjusting, "Electronic Control Unit - Flash Program" section of this manual.

9. Clear any diagnostic trouble codes that were caused by the previous procedures.

10. Verify that the ECU operates correctly.