Pinpoint Test Co: U0253:00

Normal Operation and Fault Conditions

REFER to: Communications Network - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
IPC U0253:00	Lost Communication With Accessory Protocol Interface Module: No Sub Type Information	Sets in continuous memory in the IPC if data messages received from the APIM are missing for 5 seconds or longer.

Possible Sources

Communication concern
APIM
IPC

CO1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to CO2

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.

CO2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test.
Does the APIM pass the network test?

Yes GO to CO3

No REFER to: Communications Network

CO3 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 DTC Chart: Instrument Panel Cluster (IPC) .

No GO to CO4

CO4 PERFORM THE APIM (SYNC MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the APIM self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes

No GO to CO5

CO5 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 U0253:00 still present?

Yes

GO to CO6

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.

CO6 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: 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 APIM, 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

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

Is the observable symptom still present?

Yes

GO to CO7

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

CO7 CHECK FOR CORRECT APIM (SYNC MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the APIM 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 APIM 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, Refer to APIM Guided Routine .

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.