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Pinpoint Test BM: Abs Module Communication Concern With ATCM

  1. Normal Operation and Fault Conditions 

    The selectable drive mode switch is part of the ATCM. When the drive mode switch is activated, the ATCM sends a message to the GWM over the HS-CAN2. The GWM relays the message to the ABS module over the FD-CAN. If the ABS module does not receive any messages within a certain time frame (usually less than 1 second) or if the message contains invalid information, the ABS module sets a DTC. For information on the all messages sent to the ABS module by the ATCM, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

    The auto hold switch is used to activate and deactivate the auto hold feature. The switch is an internal component of the ATCM. When the driver presses the auto hold switch, the ATCM sends an auto hold switch message to the GWM over the HS-CAN2. The GWM relays the message to the ABS module over the FD-CAN. The ABS module then waits for messages from the RCM and BCM as well as ABS sensor information to indicate the auto hold feature can be activated. Once all criteria has been met, the ABS module activates the auto hold feature.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    ABS P05D3:86 Driver Mode Select Switch 'A' Range/Performance: Signal Invalid Sets when the ATCM message indicates the selectable dive mode switch has been pressed for too long and is believed to be stuck.
    ABS U0138:00 Lost Communication with All Terrain Control Module: No Sub Type Information Sets if the ATCM messages are missing.
    ABS U0439:00 Invalid Data Received From All Terrain Control Module: No Sub Type Information Sets when the ATCM message indicates the selectable dive mode switch is faulted or not used.
    ABS U0439:86 Invalid Data Received From All Terrain Control Module: Signal Invalid Sets when the ATCM message indicates the auto hold switch is faulted or not used.

    Possible Causes 

    • Network communication concern
    • GWM
    • ATCM

  2. BM1 CHECK THE COMMUNICATION NETWORK

    • Ignition ON.

    • Using a diagnostic scan tool, retrieve the DTC s from the vehicle.
      NOTE: DTC s may be displayed from previous diagnostic actions.

    Does the ATCM module pass the network test? 

    Yes  DIAGNOSE any ATCMDTCs. REFER to: DTC Chart and Pinpoint Tests - Vehicles With: 1-Speed Torque On Demand Transfer Case . REFER to: DTC Chart and Pinpoint Tests - Vehicles With: 2-Speed Torque On Demand Transfer Case . If there are no ATCMDTCs, GO to  BM2
    No  DIAGNOSE the no communication with the ATCM. REFER to: Controller Area Network (CAN) Module Communications Network .

  3. BM2 RECHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE FOR DTC (DIAGNOSTIC TROUBLE CODE) S

    • Using a diagnostic scan tool, carry out the ABS self-test.

    • Ignition OFF.

    • Ignition ON.

    • Using a diagnostic scan tool, carry out the ABS self-test.

    • RECORD the ABS module DTC s.

    Are any of the DTC s from the Fault Trigger Conditions table present and active in the ABS module? 

    Yes  For ABS module DTC U0138:86, GO to  BM3For all others, GO to  BM4
    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.

  4. BM3 RECONFIGURE THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Ignition ON.

    • Ignition OFF.

    • Ignition ON.

    • Wait at least 1 minute.

    • Using a diagnostic scan tool, reconfigure the ABS module using As-Built Data. REFER to: Module Programming .

    • Carry out the ABS self-test.

    Do any of the DTC s in the DTC Fault Trigger Conditions Table return? 

    Yes  GO to  BM6
    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.

  5. BM4 CHECK FOR VOLTAGE-RELATED DIAGNOSTIC TROUBLE CODES (DTCS) IN THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Review the recorded Diagnostic Trouble Codes (DTCs) from the ABS module.

    Is DTC U3003:16 or U3003:17 present in the ABS module? 

    Yes  For ABS module DTC U3003:16, GO to Pinpoint Test A  For ABS module DTC U3003:17, GO to Pinpoint Test F 
    No  GO to  BM5

  6. BM5 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) IN THE ATCM (ALL TERRAIN CONTROL MODULE)

    • Ignition ON.

    • Using a diagnostic scan tool, carry out the ATCM self-test.

    Are any ATCM Diagnostic Trouble Codes (DTCs) present? 

    Yes  DIAGNOSE the ATCMDTCs. REFER to: DTC Chart and Pinpoint Tests - Vehicles With: 1-Speed Torque On Demand Transfer Case . REFER to: DTC Chart and Pinpoint Tests - Vehicles With: 2-Speed Torque On Demand Transfer Case
    (307-07A Four-Wheel Drive Systems, Diagnosis and Testing). If there are no ATCM
    No  GO to  BM6

  7. BM6 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 or the ABS module. If recent service history is found:

      • Verify the correct replacement module was installed. HVBOM may be used to verify correct part fitment.
      • Verify the configuration of replacement module was correct. Re-configure the 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 a new replacement module.

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

    Is the observable symptom still present? 

    Yes  GO to  BM7
    No  The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

  8. BM7 CHECK FOR COMMUNICATION DTC (DIAGNOSTIC TROUBLE CODE) S IN OTHER MODULES

    • Ignition ON.

    • Using a diagnostic scan tool, retrieve the DTC s from the vehicle.
      NOTE: DTC s may be displayed from previous diagnostic actions.

    Is DTC U0138:xx or U0439:xx set in 1 or more modules in addition to the ABS module? 

    Yes  GO to  BM8
    No  GO to  BM9

  9. BM8 CHECK FOR CORRECT ATCM (ALL TERRAIN CONTROL MODULE) OPERATION

    • Ignition OFF.

    • Disconnect ABS module C135.

    • 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

    • Connect ATCM C2071. Make sure the connector seats and latches correctly.

    • Connect ABS module C135. Make sure the connector 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.

  10. BM9 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION

    • Put the ABS module in sleep mode by performing the following steps:

      • With ALL doors closed, set the ignition from ON to OFF.
      • Disconnect the diagnostic scan tool.
      • Open the door, exit the vehicle and close the door.
      • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.

    • Ignition OFF.

    • Wait one minute.

    • Disconnect ABS module C135.

    • 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

    • Connect ABS module connector C135. Make sure the connector seats and latches correctly.

    • Connect ATCM C2071. Make sure the connector 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 EBB. REFER to: Electric Brake Booster (EBB) .
    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.
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