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 (brake actuator assembly) receives signals from the ECM, steering angle sensor and yaw rate and acceleration sensor (airbag sensor assembly) via CAN communication.

DTC No. Detection Item DTC Detection Condition Trouble Area
U0073 Control Module Communication Bus OFF The +BS terminal voltage is between 9.6 and a 16.5 V and a bus OFF state occurs for 0.1 seconds or more. CAN communication system
U0100 Lost Communication with ECM / PCM 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 Lost Communication with Yaw Rate Sensor Module 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 Lost Communication with Steering Angle Sensor Module 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

A01D4NCE02
A01D60YE02

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform system variant learning.

Click here

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)


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

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      EFI Communication Open ECM 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

      		 -
      Deceleration Open Acceleration 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

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      EFI Communication Open
      Yaw Rate Open
      Deceleration Open
      Steering Open
      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

    GO TO STEP 3 Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    A

  2. CHECK IF EACH CONNECTOR IS SECURELY CONNECTED (ECM, SENSOR)


    1. Turn the ignition switch off.

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

      OK
      Each connector is securely connected.
      Result
      Proceed to
      OK
      NG

    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).

      for VSC system: Click here

      for CAN communication system: Click here


      Chassis > ABS/VSC/TRC > Trouble Codes

      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
      DTCs are not output. A
      DTCs are output. B
      CAN communication system DTCs are output. C

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM 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 (brake actuator assembly) and each sensor or ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    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 DTCs are output.

      Click here

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

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B
      CAN communication system DTCs are output. C

      Tech Tips

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


    A

    END

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here