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

Note

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

Tire pressure warning light (w/ tire pressure warning system) blinks for 63 seconds and then remains on.

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

Tire pressure warning light (w/ tire pressure warning system) blinks for 63 seconds and then remains on.

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)

Tire pressure warning light (w/ tire pressure warning system) blinks for 63 seconds and then remains on.

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 (spiral cable sub-assembly)

Tire pressure warning light (w/ tire pressure warning system) is off.

WIRING DIAGRAM

C397598E01

CAUTION / NOTICE / HINT

Note:

When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration sensor zero point calibration.

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
      Tip:

      Perform the above inspection before disconnecting any sensors or connectors.

    B

    RECONFIRM DTCClick here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTORClick 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

      Tip:

      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
      Tip:

      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