The Engine Control Module (ECM) detects the following conditions:

•The ECM is unsuccessful in receiving a message from a J1939 source.
•The ECM is not receiving a valid message from a J1939 source.

Probable Causes:

1) ECM Connection/Harness
2) An ECM on the vehicle has failed or is sending improper data (Can be for anything – Cab, ABS, etc…)