Pinpoint Test Ac : U0138:00

Normal Operation and Fault Conditions

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
IPMB U0138:00	Lost Communication with All Terrain Control Module: No Sub Type Information	Sets in continuous memory in the IPMB if data messages received from the ATCM are missing for 5 seconds or longer.

Possible Sources

Communication concern
ATCM
IPMB

AC1 VERIFY THE CUSTOMER CONCERN

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to AC2

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.

AC2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test.
Does the ATCM pass the network test?

Yes GO to AC3

No REFER to: Communications Network .

AC3 PERFORM THE IPMB (IMAGE PROCESSING MODULE B) CONTROL MODULE SELF-TEST
- Using a diagnostic scan tool, perform the IPMB module self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes DIAGNOSE all non-network Diagnostic Trouble Codes (DTCs). REFER to the Diagnostic Trouble Code (DTC) Chart .

No GO to AC4

AC4 PERFORM THE ATCM (ALL TERRAIN CONTROL MODULE) SELF-TEST

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

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

Yes	REFER to: Four-Wheel Drive Systems - Vehicles Built Up To: 11-August-2020 or Four-Wheel Drive Systems - Vehicles Built From: 10-August-2020 .

GO to AC5

AC5 RECHECK THE IPMB (IMAGE PROCESSING MODULE B) DIAGNOSTIC TROUBLE CODES (DTCS)

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

Ignition OFF.

Ignition ON.

Wait 10 seconds.

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

Check the IPMB Continuous Memory Diagnostic Trouble Codes (CMDTCs).

Is DTC U0138:00 present?

Yes

GO to AC6

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.

AC6 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 ATCM module, GWM or IPMB. 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 AC7

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

AC7 CHECK FOR CORRECT ATCM (ALL TERRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the ATCM 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 ATCM 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	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 ATCM. REFER to: All Terrain Control Module (ATCM) .

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.