Tests AH: DTC U0140 - Lost Communication With Body Control Module (GEM)

PINPOINT TEST AH: DTC U0140 - LOST COMMUNICATION WITH BODY CONTROL MODULE (GEM)

AH1-AH5:

Normal Operation
The instrument cluster sets DTC U0140 in continuous memory if communication between the instrument cluster and the smart junction box (SJB) results in missing data messages for the following systems or data types:

NOTE: For a complete list of all network messages, refer to Information Bus (Module Communications Network).

- Autolock
- Auto-unlock
- Tire pressure monitoring system (TPMS)
- Backlighting dimmer input
- Door ajar status
- Headlamp on warning command
- Key-in-ignition switch
- Parking brake status
- Parking brake chime request
- Brake warning indicator request
- High beam indicator request
- Daytime running lamps (DRL)
- Brake fluid level low
- RF low beam circuit
- LF low beam circuit
- Low beam circuit
- Fog lamp relay circuit
- Autolamp switch status
- Parking lamps circuit
- Brake lamp on status
- Front fog light switch status

Once the instrument cluster sets DTC U0140, multiple indicators are likely to be inoperative in the cluster. Other modules that require data from the instrument cluster will all set communication DTCs and may also exhibit system function concerns.

Possible Causes
- Low battery voltage
- Communication network
- SJB