Possible Causes
- Wiring, terminals or connectors
- Network communication concern
- Voltage concerns
- FCIM
- GWM
- AS1: CHECK THE COMMUNICATION TO THE FCIM
- Ignition ON, engine OFF.
- Press the Read Vehicle Information button to view the results of the modules communicating on the network.
- Retrieve the continuous memory DTCs.
- Does the FCIM and the GWM pass the network test?
Yes No Go to AS2. REFER to COMMUNICATIONS NETWORK to diagnose the FCIM or the GWM does not communicate with the diagnostic scan tool. - AS2: RECHECK FOR THE ABS MODULE DTCS
- Carry out the ABS self-test.
- Clear the ABS DTCs.
- Ignition OFF.
- Ignition ON, engine OFF.
- Carry out the ABS self-test.
- Record the ABS module DTCs.
- Is DTC U0256:xx retrieved again?
Yes No Go to AS3. The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - AS3: CHECK FOR VOLTAGE DTCS IN THE ABS MODULE
- Review the recorded DTCs from the ABS module self-test.
- Is DTC U3003:16 or U3003:17 present?
Yes No For DTC U3003:17, GO to PINPOINT TEST F .
For DTC U3003:16, GO to PINPOINT TEST A .Go to AS4. - AS4: RETRIEVE ALL DTCS FROM THE GWM
- Carry out the GWM self-test.
- Record the DTCs from the GWM self-test.
- Are any DTCs present?
Yes No DIAGNOSE the GWM DTCs. REFER to COMMUNICATIONS NETWORK Go to AS5. - AS5: RETRIEVE ALL DTCS FROM THE FCIM
- Carry out the FCIM self-test.
- Record the DTCs from the FCIM self-test.
- Are any DTCs present?
Yes No DIAGNOSE the FCIM DTCs. REFER to the appropriate Information and Entertainment System - General Information article Go to AS6. - AS6: CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI or the PMI may not have been carried out.
- Check the vehicle service history for recent service actions related to the FCIM or the ABS module. If recent service history is found:
- Verify the correct replacement module was installed. HVBOM may be used to verify correct part fitment.
- Verify the configuration of replacement module was correct. Re-configure the module using as-built data if prior configuration is suspect.
- Verify the module was not obtained from a like vehicle and installed into customer vehicle. Return the swapped module to source vehicle and obtain new replacement module.
- Operate the system and determine if the observable symptom is still present.
- Is the observable symptom still present?
Yes No Go to AS7. The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration. - Check the vehicle service history for recent service actions related to the FCIM or the ABS module. If recent service history is found:
- AS7: VERIFY ALL WIRING CONNECTIONS
- Ignition OFF.
- Disconnect all FCIM electrical connectors.
- Disconnect the ABS module electrical connector.
- Disconnect all in-line electrical connectors between the ABS module and the FCIM.
- Using a good light source, inspect all disconnected electrical connectors for the following:
- corrosion - install new connector or terminal and clean the module pins
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary
- spread terminals - install new terminals as necessary
- Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals?
Yes No Go to AS8. REPAIR the connector or terminals. Refer to OEM CONNECTOR REPAIR PROCEDURES (EXCEPT ELECTRIC) , for schematic and connector information. - AS8: CHECK FOR DTC U0256:XX SET IN OTHER MODULES
- Connect all FCIM electrical connectors. Make sure they seat and latch correctly.
- Connect the ABS module electrical connector. Make sure it seats and latches correctly.
- Connect all in-line electrical connectors between the ABS module and the FCIM. Make sure they seat and latch correctly.
- Ignition ON, engine OFF.
- Press the Read Vehicle Information button to view the results of the continuous DTCs set in other modules.
- Retrieve the continuous memory DTCs.
- Review the CMDTCs from all modules.
- Is DTC U0256:xx set in 1 or more modules in addition to the ABS module?
Yes No INSTALL a new FCIM.
CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSBs address this concern, INSTALL a new FCIM. REFER to the appropriate Information and Entertainment System - General Information articleINSTALL a new ABS module.
CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSBs address this concern, INSTALL a new ABS module.