Pinpoint Test O: DTC U0155

Refer to Module Communications Network for schematic and connector information.

Normal Operation and Fault Conditions

The IPC and GSM use information contained in HS-CAN2 messages.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
GSM U0155:00	Lost Communication With Instrument Panel Cluster (IPC) Control Module: No Sub Type Information	This DTC sets if the GSM does not receive some or all of an expected message from the IPC.

Possible Sources

Communication concern
IPC
GSM

O1 CHECK THE COMMUNICATION NETWORK

Ignition ON.

Using the diagnostic scan tool, carry out the network test.

Does the IPC pass the network test?

Yes

GO to O2

No	To diagnose the module does not respond to the scan tool, REFER to: Communications Network .

O2 CHECK FOR GSM (GEAR SHIFT MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)

NOTE: If a GSM self-test is carried out, the driver door must be fully closed and locked. A false P166B DTC can set if the driver door is not fully closed or if it is unlocked during the self-test.

Clear all DTCs.

Using the diagnostic scan tool, carry out the GSM self-test.

Is DTC U0155 present?

Yes

GO to O3

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.

O3 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE GSM (GEAR SHIFT MODULE) SELF-TEST
- Check for DTCs from the self-test.
Are any non-network GSM DTCs present?

Yes RESOLVE all non-network DTCs first. REFER to DTC Chart - GSM .

No GO to O4

O4 CHECK FOR IPC (INSTRUMENT PANEL CLUSTER) DIAGNOSTIC TROUBLE CODES (DTCS)

Using the diagnostic scan tool, carry out the IPC self-test.

Check for DTCs from the self-test.

Are any non-network DTCs present?

Yes	RESOLVE all non-network DTCs first. REFER to: Instrumentation, Message Center and Warning Chimes .

GO to O5

O5 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0155 SET IN OTHER MODULES

Using the diagnostic scan tool, carry out the self-test for all modules.

Retrieve the DTCs from all modules.

Is DTC U0155 present in the PCM or SCCM?

Yes

CHECK OASIS for any applicable service articles: TSB, GSB (general service bulletin), SSM (special service message) or FSA (Field Service Action). 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 IPC. Refer to IPC Guided Routine Testing .

GO to O6

O6 CHECK FOR CORRECT GSM (GEAR SHIFT MODULE) OPERATION

NOTE: If a GSM self-test is carried out, the driver door must be fully closed and locked. A false P166B DTC can set if the driver door is not fully closed or if it is unlocked during the self-test.

Ignition OFF.

Disconnect and inspect GSM C3532 and all related in-line electrical connectors.

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

Reconnect GSM C3532 and all related in-line electrical connectors. Make sure they seat and latch correctly.

Using the diagnostic scan tool, clear all DTCs.

Carry out the GSM self-test.

Is DTC U0151 still present?

Yes

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.