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Pinpoint Test CE: Abs Module Communication Concern With HVAC Module

  1. Normal Operation and Fault Conditions 

    With the ignition ON, the HVAC control module sends messages to the GWM over the MS-CAN, the GWM relays these messages to the ABS module over the FD-CAN. If the ABS module does not receive these messages within the allotted time frame or if the messages contain invalid data, the module sets a DTC. This can be due to a HVAC control module failure, a circuit failure on the network or an excessive load on the network. For information on the messages sent to the ABS module by the HVAC control module, REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    ABS U0164:00 Lost Communication With HVAC Control Module 'A': No Sub Type Information This DTC sets when the ABS module does not receive any autohold messages from the HVAC module within the allowed time.
    ABS U0164:87 Lost Communication With HVAC Control Module 'A': Missing Message Sets when the button message from the HVAC module contains invalid or faulty information.
    ABS U0424:86 Invalid Data Received from HVAC Control Module 'A': Signal Invalid This DTC sets when the ABS module receives the autohold messages from the HVAC module, but the messages contain invalid data.

    Possible Causes 

    • Network communication concern
    • GWM
    • HVAC control module

  2. CE1 CHECK THE COMMUNICATION NETWORK

    • Ignition ON.

    • Press the Read Vehicle Information button to view the results of the modules communicating on the network.

    • Press Read Vehicle Information button to retrieve DTC's from the vehicle.
      NOTE: DTC's may be displayed from previous diagnostic actions.

    • Read vehicle information.

    Does the HVAC module pass the Network Test? 

    Yes  RETRIEVE and RECORD all HVAC module DTC's. REFER to: CLIMATE CONTROL SYSTEM - VEHICLES WITH: DUAL AUTOMATIC TEMPERATURE CONTROL (DATC) ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (EATC) . If there are no DTC's in the HVAC module: GO to  CE3
    No  GO to  CE2

  3. CE2 CHECK THE GWM (GATEWAY MODULE A) COMMUNICATION

    • Review the results of the modules communicating on the network from the previous step.

    Does the GWM pass the network test? 

    Yes  DIAGNOSE the HVAC module does not communicate with the diagnostic scan tool. REFER to: Communications Network in the appropriate Module Communications Network article.
    No  DIAGNOSE the GWM does not communicate with the diagnostic scan tool. REFER to: Communications Network in the appropriate Module Communications Network article.

  4. CE3 RECHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DTCS

    • Clear the ABS module DTC's.

    • 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 ON.

    • Carry out the ABS module self-test.

    Are any of the DTC's in the Fault Trigger Conditions Table retrieved again? 

    Yes  GO to  CE4
    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. CE4 CHECK FOR VOLTAGE DTCS IN THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Review the recorded DTC's from the ABS module self-test.

    Is DTC U3003:16 or U3003:17 present? 

    Yes  For DTC U3003:16: GO to Pinpoint Test A  For DTC U3003:17: GO to Pinpoint Test F 
    No  GO to  CE5

  6. CE5 RETRIEVE ALL DTCS FROM THE GWM (GATEWAY MODULE A)

    • Carry out the GWM self-test.

    • Record all DTC's from the GWM self-test.

    Are any DTC's present? 

    Yes  DIAGNOSE the GWM DTC. REFER to: Communications Network in the appropriate Module Communications Network article.
    No  GO to  CE6

  7. CE6 RETRIEVE ALL DTCS FROM THE HVAC (HEATING, VENTILATION AND AIR CONDITIONING) MODULE

    • Carry out the HVAC module self-test.

    • Record all DTC's from the HVAC self-test.

    Are any DTC's present? 

    Yes  DIAGNOSE the HVAC module DTC. REFER to: CLIMATE CONTROL SYSTEM - VEHICLES WITH: DUAL AUTOMATIC TEMPERATURE CONTROL (DATC) ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (EATC) .
    No  GO to  CE7

  8. CE7 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 HVAC or 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 new replacement module.

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

    Is the observable symptom still present? 

    Yes  GO to  CE8
    No  The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

  9. CE8 CHECK FOR COMMUNICATION DTCS IN OTHER MODULES

    • Ignition ON.

    • Clear the ABS module DTC's.

    • Press Read Vehicle Information button to retrieve DTC's from the vehicle.
      NOTE: DTC's may be displayed from previous diagnostic actions.

    • Read vehicle information.

    Is DTC U0164:xx or U0424:xx set in 1 or more modules in addition to the ABS module? 

    Yes  GO to  CE9
    No  GO to  CE10
    For all others: Test is complete and no faults were found.

  10. CE9 VERIFY HVAC (HEATING, VENTILATION AND AIR CONDITIONING) MODULE OPERATION

    • Ignition OFF.

    • Disconnect HVAC module connector C228A.

    • Disconnect GWM connector C2431.

    • Disconnect ABS connector 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 GWM connector C2431. Make sure the connector seats and latches correctly.

    • Connect HVAC module connector C228A. 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 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 services articles address this concern, INSTALL a new HVAC module. REFER to: CLIMATE CONTROL SYSTEM - VEHICLES WITH: DUAL AUTOMATIC TEMPERATURE CONTROL (DATC) ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (EATC) .
    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.

  11. CE10 VERIFY 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.

    • Disconnect ABS module connector C135.

    • Disconnect GWM connector C2431.

    • Disconnect HVAC module connector C228A.

    • 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 HVAC module connector C228A. Make sure the connector seats and latches correctly.

    • Connect GWM connector C2431. Make sure the connector seats and latches correctly.

    • Connect ABS module connector 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 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 unit. REFER to: Electric Brake Booster (EBB) . REFER to: Electric Brake Booster (EBB) - Full Hybrid Electric Vehicle (FHEV)/Plug-In Hybrid Electric Vehicle (PHEV) .
    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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