Pinpoint Test H: DTC U0155 (Early Build)

Information and Entertainment System

Pinpoint Test H: DTC U0155 (Early Build)

Normal Operation

The Audio Front Control Module (ACM) receives the following messages from the IPC (Instrument Panel Cluster) via the Medium Speed Controller Area Network (MS-CAN) :

- Date/time

- Vehicle speed

- Ignition switch position

- Shipment mode status

- Vehicle Identification Number (VIN)

As more than one module receives these messages, all modules receiving a particular message should exhibit a symptom if the message is missing.

- DTC U0155 (Lost Communication With IPC (Instrument Panel Cluster))- set by the ACM (Audio Front Control Module) when network messages are missing from the IPC (Instrument Panel Cluster) for more than 10 seconds with the ignition in RUN.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- IPC (Instrument Panel Cluster)

PINPOINT TEST H : DTC U0155 (EARLY BUILD)

H1 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 U0155 set in the ACM (Audio Front Control Module)?

Yes
GO to H2.

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.

H2 CHECK FOR DTC U0155 (OR DTC U0155:00) SET IN MULTIPLE MODULES

- Retrieve all continuous DTCs from all modules.

Is DTC U0155 (or DTC U0155:00) present in more than one module?

Yes
GO to H3.

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 IPC (Instrument Panel Cluster) and the ACM (Audio Front Control Module) for an intermittent fault.

H3 CHECK FOR CORRECT IPC (Instrument Panel Cluster) OPERATION

- Disconnect the IPC (Instrument Panel Cluster) connector.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the IPC (Instrument Panel Cluster) connector and make sure it seats correctly.

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

Is the concern still present?

Yes
INSTALL a new IPC (Instrument Panel Cluster). 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.