U0257

Information and Entertainment System

Pinpoint Test AC: DTC U0257:00

Normal Operation

- DTC U0257:00 (Lost Communication With Front Controls/Display Interface Module: No Sub Type Information)- set by the Audio Control Module (ACM), the Accessory Protocol Interface Module (APIM), the audio Digital Signal Processing (DSP) module (THX(R)) and the Front Controls Interface Module (FCIM) when it is missing network messages from the Front Control/Display Interface Module (FCDIM) over the Infotainment Controller Area Network (I-CAN) for more than 5 seconds with the ignition in the RUN position.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- Audio system concern

- FCDIM (Front Control/Display Interface Module)

PINPOINT TEST AC : DTC U0257:00

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 U0257:00 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 high network traffic or an intermittent fault condition.

AC2 CHECK FOR BATTERY VOLTAGE OUT-OF-RANGE DTCs

- Carry out the self-test for the following modules:
- ACM (Audio Control Module)

- APIM (Accessory Protocol Interface Module)

- Audio DSP (Digital Signal Processing) module

- FCIM (Front Controls Interface Module)

- FCDIM (Front Control/Display Interface Module)

Is DTC U3003:16 or U3003:17 recorded in any module?

Yes
For an audio system module, REFER to DTC Charts Accessories and Optional Equipment.

No
GO to AC3.

AC3 CHECK FOR DTC U0257:00 SET IN MULTIPLE MODULES

- Review the recorded results from the self-test.

Is DTC U0257:00 set in more than one module?

Yes
GO to AC4.

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

If there is no observable symptom, CHECK the I-CAN (Infotainment Controller Area Network) wiring between the FCDIM (Front Control/Display Interface Module) and the module in question for an intermittent fault.

AC4 CHECK FOR CORRECT FCDIM (Front Control/Display Interface Module) OPERATION

- Ignition OFF.

- Disconnect the FCDIM (Front Control/Display Interface Module) connector.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the FCDIM (Front Control/Display Interface Module) 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 FCDIM (Front Control/Display Interface Module). REFER to Front Controls/Display Interface Module (FCDIM) . 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.