ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:U0073

DTC Code DTC Name
U0073 Control Module Communication Bus OFF

DESCRIPTION

The skid control ECU (brake actuator assembly) receives signals from the ECM via the CAN communication system.

DTC No. Detection Item DTC Detection Condition Trouble Area
U0073 Control Module Communication Bus OFF The condition that the bus OFF state occurs once or more within 0.1 seconds occurs 10 times in succession while the voltage at the IG1 terminal is between 10 and 17.4 V. (Sent signals cannot be received.) CAN communication system

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 Normal or Error Normal Error: Momentary interruption

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      EFI Communication Open

      Tech Tips

      Perform the above inspection before removing the sensor and connector.

      Result
      Proceed to
      There is a constant open circuit
      There are no momentary interruptions
      There are momentary interruptions

    There are no momentary interruptions

    GO TO STEP 3 Click here

    There are momentary interruptions

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    There is a constant open circuit

  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.
      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 ABS and CAN communication).

      for ABS: Click here

      for CAN communication system: Click here


      Chassis > ABS/VSC/TRC > Trouble Codes

      Tech Tips

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

      Result
      Result Proceed to
      DTC (relating to CAN communication system) is output A
      DTC (relating to ABS) is output B
      DTC is not output C

    A

    CHECK CAN COMMUNICATION SYSTEM Click here

    B

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

    C

    USE SIMULATION METHOD TO CHECK 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 interruption between the skid control ECU (brake actuator assembly) and each sensor or ECM.

      Click here

    4. Check that there is no momentary interruption.

      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. 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 DTC is output.

      Click here

    6. If ABS DTCs are output, record them.


      Chassis > ABS/VSC/TRC > Trouble Codes

      Tech Tips

      The CAN communication system must be normal when repairing each sensor DTC (for ABS).

      Result
      Proceed to
      DTC is not output
      DTC is output (relating to ABS)
      DTC is output (relating to CAN communication system)

    DTC is not output

    END

    DTC is output (relating to ABS)

    REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

    DTC is output (relating to CAN communication system)

    CHECK CAN COMMUNICATION SYSTEM Click here