Pinpoint Test H: DTC U0155

Information and Entertainment System

Pinpoint Tests

Pinpoint Test H: DTC U0155

Normal Operation

The Audio Control Module (ACM) receives the following messages from the Instrument Cluster (IC) 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 Instrument Panel Cluster ( IPC)) - set by the ACM when network messages are missing from the IC for greater than 10 seconds with the ignition in RUN.

This pinpoint test is intended to diagnose the following:

- Communication network concern
- IC


PINPOINT TEST H: DTC U0155

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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 self-test using the scan tool.
- Is DTC U0155 set in the ACM?

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.

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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 to diagnose the observed symptom. Information and Entertainment Systems

If there is no observable symptom, CHECK the MS-CAN wiring between the IC and the ACM for an intermittent fault.

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H3 CHECK FOR CORRECT IC OPERATION


- Disconnect the IC connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the IC 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 IC. REFER to Instrumentation and Warning Chimes Service and Repair. 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.

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