FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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No Communication With ECM

Symptom:
NO COMMUNICATION WITH ECM

Test 1-3:




Test 4-6:





When Monitored:
Ignition On - Continuously

Set Condition:
When the CAB fails to receive all messages from the ECM.

POSSIBLE CAUSES
- NO COMMUNICATION WITH BUS
- ENGINE CONTROL MODULE DTC(S) PRESENT
- ENGINE CONTROL MODULES POWER/GROUND CIRCUIT(S) SHORTED OR OPEN
- CAN C BUS (+)/CAN C BUS () CIRCUIT(S) OPEN TO ENGINE CONTROL MODULE
- CAN C BUS (+)/CAN C BUS () CIRCUIT(S) OPEN TO CAB
- ANTILOCK BRAKE CONTROLLER
- ENGINE CONTROL MODULE