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 receives the signals from the ECM, steering angle sensor (spiral with sensor cable sub-assembly) and yaw rate and acceleration sensor (yaw rate sensor) via the CAN communication system.

DTC Code

DTC Detection Condition

Trouble Area

U0073

The +BS terminal voltage is between 9.6 and 16.5 V and a bus OFF state occurs 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 sensor

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 (spiral with sensor cable sub-assembly)

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).

      Table 1. ABS/VSC/TRC

      Tester Display

      Measurement Item/Range

      Normal Condition

      Diagnostic Note

      EFI Communication Open

      EFI communication open detection/ Error or Normal

      Normal: Normal

      Error: Momentary interruption

      Yaw Rate Open

      Yaw rate sensor open detection/ Error or Normal

      Normal: Normal

      Error: Momentary interruption

      Deceleration Open

      Acceleration sensor open detection / Error or Normal

      Normal: Normal

      Error: Momentary interruption

      Steering Open

      Steering angle sensor open detection/ Error or Normal

      Normal: Normal

      Error: Momentary interruption

      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.

    RECONFIRM DTCClick here

    REPAIR OR REPLACE HARNESS OR CONNECTORClick here

  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.

    CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY

  3. RECONFIRM DTC

    1. Turn the ignition switch off.

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

      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

    USE SIMULATION METHOD TO CHECK

    (Click here)

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC

    (Click here)

    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 that there is no momentary interruption between the skid control ECU (brake actuator assembly) and each sensor or ECM (Click here).

  5. RECONFIRM DTC

    1. Turn the ignition switch off.

    2. Clear the DTCs (Click here).

    3. Start the engine.

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

    5. Check that no CAN communication system DTCs are output (Click here).

    6. If ABS and VSC DTCs are output, record them (Click here).

      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).

    END

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC

    (Click here)

    INSPECT CAN COMMUNICATION SYSTEM

    (Click here)