Pinpoint Test Ah: U0256:00

AH1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to AH2

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.

AH2 PERFORM A NETWORK TEST
- Using a diagnostic scan tool, perform a network test.
Does the FCIM pass the network test?

Yes GO to AH3

No Refer to: Communications Network .

AH3 PERFORM THE PAM (PARKING ASSIST CONTROL MODULE) SELF-TEST

Using a diagnostic scan tool, perform the PAM self-test.

Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes	DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). Refer to DTC Chart: Parking Aid Module (PAM) .

GO to AH4

AH4 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 non-network Diagnostic Trouble Codes (DTCs) recorded?

Yes Refer to: Communications Network .

No GO to AH5

AH5 PERFORM THE FCIM (FRONT CONTROLS INTERFACE MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the FCIM self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?

Yes Refer to: Information and Entertainment System .

No GO to AH6

AH6 RECHECK THE PAM (PARKING ASSIST CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, clear the PAM Diagnostic Trouble Codes (DTCs).

Ignition OFF.

Ignition ON.

Wait 10 seconds.

Using a diagnostic scan tool, perform the continuous memory self-test.

Check the PAM Diagnostic Trouble Codes (DTCs).

Is DTC U0256:00 present?

Yes

GO to AH7

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.

AH7 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, GWM or PAM. If recent service history is found:
- verify correct replacement module was installed
  - vehicle parts build 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
  - if a new replacement module is installed, PERFORM PMI using as-built data

Operate the system and determine if the observable symptom is still present.

Is the observable symptom still present?

Yes

GO to AH8

No	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

AH8 CHECK FOR CORRECT FCIM (FRONT CONTROLS INTERFACE MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all 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. Refer to: Front Controls Interface Module (FCIM) .

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.