DESCRIPTION:
This fault code sets when the motor control module (MCM) stops receiving messages from the aftertreatment control module (ACM).

MONITORED PARAMETER:
ACM controller area network (CAN) communication.

TYPICAL ENABLING CONDITIONS:
Always enabled

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Always enabled

TYPICAL DURATION:
Two seconds

DASH LAMPS:
1. MIL is solid
2. CEL and AWL Flash

ENGINE REACTION:
30 seconds shutdown.

VERIFICATION:
1. Turn the ignition off.
2. Disconnector the USB link from the 9 – pin connector.
3. Wait five minutes.
4. Reconnect the USB link and diagnostic service tool.
5. Turn the ignition on and recheck for the fault code.

NOTE: If there are any battery voltacodes, fix those first. If the ECM has been programmed recently, clear codes, test drive, and release vehicle if they don’t come back.

PROBABLE CAUSES:
1. Powertrain Controller Area Network (PTCAN) harness.
2. ACM (computer) failure.
3. CPC (computer) failure.
4. Wiring between the CPC and the ACM.
5. ACM/CPC not getting voltage.