Pinpoint Test L: U0155

Normal Operation and Fault Conditions

If the PCM does not receive messages from other modules within a certain time frame the PCM sets a DTC for lost communication.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM U0155:00	Lost Communication With Instrument Panel Cluster (IPC) Control Module: No Sub Type Information	Sets when the PCM does not receive the IPC message within the defined amount of time.

Possible Sources

Communications network concern
IPC module
GWM
PCM

L1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to L2

No	The system is operating normally at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.

L2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform a network test.
Did the module pass the network test?

Yes GO to L3

No REFER to: Controller Area Network (CAN) Module Communications Network

L3 PERFORM IPC CONTROL MODULE SELF-TEST
- Using a diagnostic scan tool, perform a IPC control module self-test.
Are any DTC s recorded?

Yes REFER to: Controller Area Network (CAN) Module Communications Network

No GO to L4

L4 CHECK THE GWM DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, retrieve the GWMDTC s.
Are any DTC s recorded?

Yes REFER to: Controller Area Network (CAN) Module Communications Network

No GO to L5

L5 PERFORM THE PCM SELF-TEST
- Using a diagnostic scan tool, perform the PCM self-test.
Are any non-network DTC s present?

Yes REFER to Diagnostic Trouble Code (DTC) Chart .

No GO to L6

L6 RECHECK THE PCM DIAGNOSTIC TROUBLE CODES (DTCS)

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.

Using a diagnostic scan tool, clear the DTC s.

Wait 10 seconds.

Repeat the PCM self-test.

Is DTC U0155 still present?

Yes

GO to L7

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.

L7 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 ABS, BCM, GWM, IPC MODULE, or PCM. If recent service history is found:
- verify correct replacement module was installed
  - HVBOM may be used to verify correct part fit
- 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 L8

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

L8 CHECK FOR CORRECT IPC MODULE OPERATION

Ignition OFF.

Disconnect and inspect the IPC control module connector.

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 IPC control module connector. Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	INSTALL a new IPC. REFER to: Instrument Panel Cluster (IPC)

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.