Pinpoint Test Z: DTC U0256:00

Information and Entertainment System

Pinpoint Test Z: DTC U0256:00

Normal Operation

- DTC U0256:00 (Lost Communication With Front Controls Interface Module: No Sub Type Information)- set by the Audio Control Module (ACM) or Accessory Protocol Interface Module (APIM) when network messages are missing from the Front Controls Interface Module (FCIM) over the MS-CAN (Medium Speed Controller Area Network) for greater than 5 seconds with the ignition in the RUN position.

This pinpoint test is intended to diagnose the following:

- Communication network concern

- ACM (Audio Control Module)

- FCIM (Front Controls Interface Module)

- APIM (Accessory Protocol Interface Module)

PINPOINT TEST Z : DTC U0256:00

NOTE: Disregard the pinpoint test steps for the APIM (Accessory Protocol Interface Module) if the concern is on a vehicle without the SYNC system.

Z1 CHECK THE ACM (Audio Control Module) AND APIM (Accessory Protocol Interface Module) DTCs

NOTE: If new modules were installed prior to the DTC being set, the module configuration may be incorrectly set during Programmable Module Installation (PMI) or the PMI (Programmable Module Installation) may not have been carried out.

- Clear the ACM (Audio Control Module) and APIM (Accessory Protocol Interface Module) DTCs.

- Ignition OFF.

- Ignition ON.

- Wait at least 10 seconds.

- Repeat the ACM (Audio Control Module) and APIM (Accessory Protocol Interface Module) self-tests.

Is DTC U0256:00 still present?

Yes
GO to Z2.

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

Z2 VERIFY THE CUSTOMER CONCERN

- Ignition ON.

- Verify that there is an observable symptom present.

Is an observable symptom present?

Yes
GO to Z3.

No
The system is operating correctly at this time. The DTC may have been set due to an intermittent fault in the network wiring. CHECK the MS-CAN (Medium Speed Controller Area Network) wiring between the FCIM (Front Controls Interface Module) and the module in question for an intermittent fault.

Z3 CHECK THE COMMUNICATION NETWORK

- Ignition ON.

- Carry out the network test using the scan tool.

Does the FCIM (Front Controls Interface Module) pass the network test?

Yes
GO to Z4.

No
REFER to Information Bus.

Z4 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)

- FCIM (Front Controls Interface Module)

Is DTC B1316, B1317, U3003:16 or U3003:17 recorded in any module?

Yes
REFER to DTC Charts. Accessories and Optional Equipment

No
INSTALL a new FCIM (Front Controls Interface Module). REFER to Front Controls Interface Module (FCIM) - Without Navigation or Front Controls Interface Module (FCIM) - With Navigation . CLEAR the ACM (Audio Control Module) and APIM (Accessory Protocol Interface Module) DTCs. REPEAT the ACM (Audio Control Module) and APIM (Accessory Protocol Interface Module) self-tests.

If DTC U0256:00 is still present in the ACM (Audio Control Module), INSTALL a new ACM (Audio Control Module). REFER to Audio Control Module (ACM) . TEST the system for normal operation.

If DTC U0256:00 is still present in the APIM (Accessory Protocol Interface Module), INSTALL a new APIM (Accessory Protocol Interface Module). REFER to Accessory Protocol Interface Module (APIM) . TEST the system for normal operation.