Pinpoint Test Cp: U0256:00
- Normal Operation and Fault Conditions
REFER to: Communications Network - System Operation and Component Description .
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition IPC U0256:00 Lost Communication With Front Controls Interface Module 'A': No Sub Type Information Sets in continuous memory in the IPC if data messages received from the FCIM through the GWM are missing for 5 seconds or longer. Possible Sources
- Communication concern
- GWM concern
- FCIM
- IPC
- CP1 VERIFY THE CUSTOMER CONCERN
- Ignition ON.
- Verify there is an observable symptom present.
Is an observable symptom present?
Yes GO to CP2 No CLEAR the DTC. The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - CP2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test.
Does the FCIM pass the network test?
Yes GO to CP3 No REFER to: Communications Network . - CP3 PERFORM THE IPC (INSTRUMENT PANEL CLUSTER) SELF-TEST
- Using a diagnostic scan tool, perform the IPC self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?
Yes REFER to Diagnostic Trouble Code (DTC) Chart No GO to CP4 - CP4 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (CMDTCs).
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to: Communications Network . No GO to CP5 - CP5 PERFORM THE FCIM (FRONT CONTROLS INTERFACE MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the FCIM self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?
Yes No GO to CP6 - CP6 RECHECK THE IPC (INSTRUMENT PANEL CLUSTER) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, clear the IPC Diagnostic Trouble Codes (DTCs).
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Using a diagnostic scan tool, perform the continuous memory self-test.
- Check the IPC Diagnostic Trouble Codes (DTCs).
Is DTC U0256:00 still present?
Yes GO to CP7 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. - CP7 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERNNOTE: If new modules were installed prior to the DTC being set, the module configuration may 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, GWM or IPC. If recent service history is found:
- verify correct replacement module was installed
- HVBOM may be used to verify correct part fitment
- verify the configuration of replacement module was correct
- re-configure 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
- verify correct replacement module was installed
- Operate the system and determine if the observable symptom is still present.
Is the observable symptom still present?
Yes GO to CP8 No 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, GWM or IPC. If recent service history is found:
- CP8 CHECK FOR CORRECT FCIM (FRONT CONTROLS INTERFACE MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect the FCIM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the FCIM connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new FCIM. If not equipped with a touchscreen, If equipped with a touchscreen, No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.