DESCRIPTION:
Powertrain controller area network DM1 message not received or has stopped arriving.

MONITORED PARAMETER:
CAN communication

TYPICAL ENABLING CONDITIONS:
Always enabled

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Always enabled

TYPICAL DURATION:
2 seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
None

NOTE: If there are any battery related faults, repair those first.

PROBABLE CAUSES:
1. If any engine components have been programmed recently and are inactive, clear then and test drive to see if they return.
2. Turn ignition off for 5 minutes (leave batteries connected) and turn back on to see if they went inactive.
3. Measure resistance across MCM 12-pin connector at pins 13 and 19. If less than 5 ohms, replace the Power Train CAN harness.
4. ACM Failure.
5. CPC Failure.
6. Wiring between the ACM, CPC, and MCM.
7. MCM Failure.