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Home >> Lincoln >> 2024 >> Aviator Reserve, AWD >> Repair and Diagnosis (Single Page) >> Brakes >> Traction Control >> Anti-Lock Brake System (Abs) And Stability Control (Pinpoint Tests AO - BS) >> Diagnosis And Testing >> Anti-Lock Brake System (ABS) and Stability Control >> Pinpoint Tests >> Pinpoint Test BG: Abs (Anti-Lock Brake System) Module Communication Concern With The RCM (Restraints Control Module) >> Pinpoint Test BG: Abs (Anti-Lock Brake System) Module Communication Concern With The RCM (Restraints Control Module)

Pinpoint Test BG: Abs (Anti-Lock Brake System) Module Communication Concern With The RCM (Restraints Control Module)

  1. Refer to Module Communications Network for schematic and connector information.

    Normal Operation and Fault Conditions 

    With the ignition ON, the RCM sends messages to the ABS module over the HS-CAN2. If the ABS module does not receive these messages within a certain time frame, the ABS module sets a DTC. For information on the messages sent to the ABS module by the RCM, 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 U0151:00 Lost Communication With Restraints Control Module: No Sub Type Information Sets if the time allotted for stability sensor messages expires before the ABS module receives any stability sensor messages.
    ABS U0151:82 Lost Communication With Restraints Control Module: Alive/Sequence Counter Incorrect/Not Updated Sets if the acceleration data message is received with no change in the signal value counter for any of the stability sensors.
    ABS U0151:83 Lost Communication With Restraints Control Module: Value Of Signal Protection Calculation Incorrect Sets if the acceleration data message received contains invalid stability sensor information.
    ABS U0151:87 Lost Communication With Restraints Control Module: Missing Message Sets if the acceleration data message is missing for more than the allotted time.
    ABS U0452:00 Invalid Data Received From Restraints Control Module: No Sub Type Information Sets if the ABS module recieves invalid longitudinal acceleration data from the RCM. This can be due to an incorrectly installed RCM, an RCM that has not been initialized, or an internal failure of the sensor.
    ABS U0452:86 Invalid Data Received From Restraints Control Module: Signal Invalid Sets if the yaw rate, roll rate, longitudinal acceleration or lateral acceleration counter signal message from the RCM does not update.

    Possible Causes 

    • Network communication concern
    • RCM

  2. BG1 CHECK THE COMMUNICATION NETWORK

    • Ignition ON.

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

    • NOTE: DTCs may be displayed from previous diagnostic actions.

    Does the RCM pass the network test? 

    Yes  RETRIEVE and RECORD all RCM DTCs. REFER to AIRBAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS) . If there are no DTCs in the RCM, GO to  BG2.
    No  DIAGNOSE the no communication with the RCM. REFER to DIAGNOSIS AND TESTING .

  3. BG2 RECHECK FOR THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DTCS

    • 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.

    • Record all ABS module DTCs.

    Is any DTC from the DTC Fault Trigger Conditions table retrieved again? 

    Yes  GO to  BG3.
    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. BG3 CHECK FOR VOLTAGE DTCS IN THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE

    • Review the recorded DTCs from the ABS module self-test.

    Is DTC U3003:16 or U3003:17 present? 

    Yes  REFER to the DIAGNOSTIC TROUBLE CODE (DTC) CHART
    No  GO to  BG4.

  5. BG4 CHECK FOR DTCS IN THE RCM (RESTRAINTS CONTROL MODULE)

    • Record all DTCs from the RCM self-test.

    Are any DTCs present? 

    Yes  DIAGNOSE the RCM DTCs. REFER to AIRBAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS) .
    No  GO to  BG5.

  6. BG5 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 RCM 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 new replacement module.

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

    Is the observable symptom still present? 

    Yes  GO to  BG6.
    No  The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

  7. BG6 CHECK FOR LOST COMMUNICATION DTCS SET IN OTHER MODULES

    • Ignition ON.

    • NOTE: DTCs may be displayed from previous diagnostic actions.

    Is DTC U0151xx or U0452:xx set in 1 or more modules in addition to the ABS module? 

    Yes  GO to  BG7.
    No  GO to  BG8.

  8. BG7 CHECK FOR CORRECT RCM (RESTRAINTS CONTROL MODULE) OPERATION

    WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

    • 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.

    • Wait one minute.

    • Disconnect ABS-A Module connector.

    • Disconnect ABS-B Module connector.

    • Disconnect RCM-A connector.

    • Disconnect RCM-B connector.

    • 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-B Module connector. Make sure the connector seats and latches correctly.

    • Connect ABS-A Module connector. Make sure the connector seats and latches correctly.

    • Connect RCM-B connector. Make sure the connector seats and latches correctly.

    • Connect RCM-A connector. 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 RCM. REFER to: AIRBAG SUPPLEMENTAL RESTRAINT SYSTEM (SRS) .
    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.

  9. BG8 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) OPERATION

    WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

    • 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.

    • Wait one minute.

    • Disconnect RCM-A connector.

    • Disconnect RCM-B connector.

    • Disconnect ABS-A Module connector.

    • Disconnect ABS-B Module connector.

    • 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 RCM-B connector. Make sure the connector seats and latches correctly.

    • Connect RCM-A connector. Make sure the connector seats and latches correctly.

    • Connect ABS-B Module connector. Make sure the connector seats and latches correctly.

    • Connect ABS-A Module connector. 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  The HCU and ABS module are a single assembly known as the EBB unit. 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) .
    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.
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