ROTOR AS 4544879 - Caterpillar

Probable Causes
Electrical connectors
Electronic Control Module (ECM)
Cat Data Link
CAN data link (if applicable)Recommended Actions
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. If the ECM does not communicate with Cat ET, refer to Troubleshooting, "Electronic Service Tool Will Not Communicate with ECM".
Check for the correct installation of the electrical connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Troubleshoot the Cat Data Link for possible faults. Refer to the diagnostic functional test Troubleshooting, "Data Link Circuit - Test".
Verify that the CAN data link does not have an open or short circuit. Refer to the diagnostic functional test Troubleshooting, "CAN Data Link Circuit - Test".