VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:U0073, U0100, U0123, U0126

DTC Code DTC Name
U0073 Control Module Communication Bus OFF
U0100 Lost Communication with ECM / PCM
U0123 Lost Communication with Yaw Rate Sensor Module
U0126 Lost Communication with Steering Angle Sensor Module

DESCRIPTION

The skid control ECU receives signals from the ECM, steering angle sensor and yaw rate and acceleration sensor (airbag sensor assembly) via the CAN communication system.

DTC No. DTC Detection Condition Trouble Area
U0073 The +BS terminal voltage is between 9.6 and 16.5 V and bus off is judged for 0.1 seconds or more. CAN communication system
U0100 The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle speed is 6 km/h (4 mph) or more, and signals cannot be sent to the ECM for 2.5 seconds or more.

  • CAN communication system

  • Skid control ECU (Brake actuator assembly)

  • ECM
U0123 The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle speed is 6 km/h (4 mph) or more, and signals from the yaw rate and acceleration sensor cannot be received for 1.1 seconds or more.

  • CAN communication system

  • Skid control ECU (Brake actuator assembly)

  • Yaw rate and acceleration sensor (Airbag sensor assembly)
U0126 The +BS terminal voltage is between 9.6 and 16.5 V, the vehicle speed is 6 km/h (4 mph) or more, and signals from the steering angle sensor cannot be received for 1.1 seconds or more.

  • CAN communication system

  • Skid control ECU (Brake actuator assembly)

  • Steering angle sensor

WIRING DIAGRAM

A01HMQ5E10

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)


    1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC Click here.

      ABS/VSC/TRAC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      EFI Communication Open EFI communication open detection / Error or Normal

      Error: Momentary interruption

      Normal: Normal

      		 -
      Yaw Rate Open Yaw rate sensor open detection / Error or Normal

      Error: Momentary interruption

      Normal: Normal

      		 -
      Steering Open Steering angle sensor open detection / Error or Normal

      Error: Momentary interruption

      Normal: Normal

      		 -
      Result
      Result Proceed to
      There is a constant interruption. (Error is displayed without interruption) A
      There are no momentary interruptions. B
      There are momentary interruptions. (Error is displayed intermittently) C

      Tech Tips

      Perform the above inspection before disconnecting any sensors or connectors.


    B

    RECONFIRM DTC Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    A

  2. CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED


    1. Turn the ignition switch off.

    2. Check if each sensor or ECM connector is securely connected.

      OK
      Each connector is securely connected.

    NG

    CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY

    OK

  3. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Record the output DTCs (for VSC system and/or CAN communication system) Click here for VSC system, or Click here for CAN communication system).

      Tech Tips

      If CAN communication system DTCs and related sensor DTCs are output simultaneously, troubleshoot the DTCs (for VSC system) after the CAN communication system returns to normal.

      Result
      Result Proceed to
      DTC is not output. A
      DTC is output. B
      CAN communication system DTC is output. C

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  4. REPAIR OR REPLACE HARNESS OR CONNECTOR


    1. Turn the ignition switch off.

    2. Repair or replace the harness or connector.

    3. Check for any momentary interruptions between the skid control ECU and each sensor or ECM Click here.


    NEXT

  5. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Clear the DTCs Click here.

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Drive the vehicle at a speed of 15 km/h (9 mph) or more and turn the steering wheel to the right and left.

    6. Check that no CAN communication system DTC is output Click here.

    7. If VSC system DTCs are output, record them Click here.

      Result
      Result Proceed to
      DTC is not output. A
      DTC is output. B
      CAN communication system DTC is output. C

      Tech Tips

      The CAN communication system must be normal when performing troubleshooting for sensor DTCs (for VSC system).


    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here

    A

    END