TUBE AS 8S0481 - Caterpillar

Probable Causes
Electronic Control Module (ECM)
Power to the ECMData Link
Problem in the circuit for the Cat Data Link or the CAN data linkElectrical connectors
Installation of electrical connectorsRecommended Actions
Power to the ECM
Check for power to the ECM. Refer to Troubleshooting, "Electrical Power Supply - Test".Connect Caterpillar Electronic Technician (ET) to the service tool connector. If the ECM does not communicate with Cat ET, refer to service Troubleshooting, "Electronic Service Tool Does Not Communicate".Problem in the Circuit for the Cat Data Link or the CAN Data Link
Verify that the data link does not have an open or short circuit. Refer to the circuit tests Troubleshooting, "Cat Data Link - Test" or refer to the circuit tests Troubleshooting, "CAN Data Link - Test".Installation of Electrical Connectors
Check for correct installation of the J1/P1 and J2/P2 ECM connectors. Check for correct installation of all other applicable connectors. Refer to service Troubleshooting, "Electrical Connectors - Inspect".