Accessories and Optional Equipment
Information and Entertainment System
Pinpoint Test AC: DTC U0155 Or DTC U0155:00
Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information [1][2]Diagrams By Number.
Normal Operation
Several audio system modules receive network messages from the Instrument Panel Cluster (IPC) via the Medium Speed Controller Area Network (MS-CAN). The following information is included in the messages:
- English/metric units
- Vehicle Identification Number (VIN)
- Transmission gear selected
- Vehicle speed
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 (Instrument Panel Cluster (IPC)))- set by the Front Display Interface Module (FDIM) when network messages are missing from the IPC (Instrument Panel Cluster) for greater than 5 seconds with the ignition in RUN.
- DTC U0155:00 (Lost Communication With Instrument Panel Cluster (IPC (Instrument Panel Cluster)) Control Module: No Sub Type Information) set by the Audio Front Control Module (ACM) , the Global Positioning System Module (GPSM) , or the Accessory Protocol Interface Module (APIM) when network messages are missing from the IPC (Instrument Panel Cluster) for greater than 5 seconds with the ignition in RUN.
This pinpoint test is intended to diagnose the following:
- Communication network concern
- Audio system concern
- IPC (Instrument Panel Cluster)
PINPOINT TEST AC : DTC U0155 OR DTC U0155:00
AC1 CHECK FOR LOST COMMUNICATION DTCs
- Ignition ON.
- Clear continuous DTCs from all modules.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Retrieve all continuous DTCs from all modules.
Is DTC U0155 or DTC U0155:00 set in any audio system module?
Yes
GO to AC2.
No
The system is operating correctly at this time. The DTC may have been set due to an intermittent fault in the network wiring.
AC2 CHECK FOR BATTERY VOLTAGE OUT-OF-RANGE DTCs
- Carry out the self-test for the following modules:
- ACM (Audio Front Control Module)
- APIM (Accessory Protocol Interface Module) (if equipped)
- FDIM (Front Display Interface Module) (navigation only)
- GPSM (Global Positioning System Module) (if equipped)
- IPC (Instrument Panel Cluster)
Is DTC B1318, U3003:16, or U3003:17 recorded in any module?
Yes
For an audio system module, REFER to DTC Charts Accessories and Optional Equipment.
For the IPC (Instrument Panel Cluster) , REFER to Instrument Panel, Gauges and Warning Indicators.
No
GO to AC3.
AC3 CHECK FOR DTC U0155 OR DTC U0155:00 SET IN MULTIPLE MODULES
- Review the recorded results from the self-test.
Is DTC U0155 or DTC U0155:00 set in more than one audio system module?
Yes
GO to AC4.
No
If there is an observable symptom, GO to Symptom Chart - General Audio System to diagnose the observed symptom Symptom Chart - General Audio System.
If there is no observable symptom, CHECK the MS-CAN (Medium Speed Controller Area Network) wiring between the SJB (Smart Junction Box) and the module in question for a fault.
AC4 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.
Is the concern still present?
Yes
INSTALL a new IPC (Instrument Panel Cluster). CLEAR all continuous 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 all continuous DTCs. REPEAT the self-test for the module(s) that set DTC U0155 or DTC U0155:00.