Accessories and Optional Equipment

Information and Entertainment System

Pinpoint Test G: DTC U0140 (Early Build)

Normal Operation

The Audio Front Control Module (ACM) receives the door ajar status, as well as certain other messages, from the Generic Electronic Module (GEM) via the MS-CAN (Medium Speed Controller Area Network).

As more than one module receives these messages, all modules receiving a particular message should exhibit a symptom if the message is missing. The IPC (Instrument Panel Cluster) may also display a warning message.

- DTC U0140 (Lost Communication With Body Control Module - GEM (Generic Electronic Module))- set by the ACM (Audio Front Control Module) when network messages are missing from the GEM (Generic Electronic Module) for more than 10 seconds with the ignition in RUN.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- GEM (Generic Electronic Module)

PINPOINT TEST G : DTC U0140 (EARLY BUILD)

G1 CHECK FOR A HARD FAULT

- Ignition ON.

- Clear continuous DTCs from all modules.

- Ignition OFF.

- Ignition ON.

- Wait at least 10 seconds.

- Carry out the ACM (Audio Front Control Module) self-test using the scan tool.

Is DTC U0140 set in the ACM (Audio Front Control Module)?

Yes
GO to G2.

No
The system is operating correctly at this time. The DTC may have been set due to a prior low voltage condition or due to an intermittent fault in the network wiring.

G2 CHECK FOR DTC U0140 (OR DTC U0140:00) SET IN MULTIPLE MODULES

- Retrieve all continuous DTCs from all modules.

Is DTC U0140 (or DTC U0140:00) present in more than one module?

Yes
GO to G3.

No
If there is an observable audio symptom, GO to Symptom Chart - General Audio System to diagnose the observed symptom. Symptom Related Diagnostic Procedures

If there is no observable symptom, CHECK the MS-CAN (Medium Speed Controller Area Network) wiring between the GEM (Generic Electronic Module) and the ACM (Audio Front Control Module) for an intermittent fault.

G3 CHECK FOR CORRECT GEM (Generic Electronic Module) OPERATION

- Disconnect all the GEM (Generic Electronic Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the GEM (Generic Electronic Module) connectors and make sure they seat correctly.

- Operate the system and determine if the concern is still present.

Is the concern still present?

Yes
INSTALL a new GEM (Generic Electronic Module). CLEAR the DTCs. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs.