Pinpoint Test An: DTC U0256 Or DTC U0255:00

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Disregard the pinpoint test steps for the APIM if the concern is on a vehicle without the SYNC system.

AN1 CHECK THE ACM AND FDIM 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 may not have been carried out.
- Clear the ACM and APIM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Repeat the ACM and APIM self-tests.
- Is DTC U0256 or DTC U0255:00 still present?
- Yes : GO to AN2.
- No : The system is operating correctly at this time. The DTC may have been set due to an intermittent fault in the network wiring.
AN2 VERIFY THE CUSTOMER CONCERN
- Ignition ON.
- Verify that there is an observable symptom present.
- Is an observable symptom present?
- Yes : GO to AN3.
- 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 wiring between the FDIM and the module in question for an intermittent fault.
AN3 CHECK THE COMMUNICATION NETWORK
- Ignition ON.
- Carry out the network test using the scan tool.
- Does the FDIM pass the network test?
- Yes : GO to AN4.
- No : REFER to MODULE COMMUNICATIONS NETWORK .
AN4 CHECK FOR BATTERY VOLTAGE OUT-OF-RANGE DTCs
- Carry out the self-test for the following modules:
  - ACM
  - APIM
  - FDIM
- Is DTC B1316, B1317, U3003:16 or U3003:17 recorded in any module?
- Yes : REFER to DTC TABLES .
- No : INSTALL a new FDIM . REFER to FRONT DISPLAY INTERFACE MODULE (FDIM) - FUSION, MILAN or FRONT DISPLAY INTERFACE MODULE (FDIM) - MKZ . CLEAR the ACM and APIM DTCs. REPEAT the ACM and APIM self-tests.
  If DTC U0256 (Fusion, Milan) or DTC U0255:00 (MKZ) is still present in the ACM , INSTALL a new ACM . REFER to AUDIO CONTROL MODULE (ACM) - FUSION, MILAN or AUDIO CONTROL MODULE (ACM) - MKZ . TEST the system for normal operation.
  
  If DTC U0256:00 is still present in the APIM , INSTALL a new APIM . REFER to ACCESSORY PROTOCOL INTERFACE MODULE (APIM) . TEST the system for normal operation.