ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1257

DTC Code DTC Name
C1257 Power Supply Drive Circuit

DESCRIPTION

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

DTC Code DTC Detection Condition Trouble Area
C1257 There is an open in the motor system circuit (motor input circuit). Skid control ECU (Master cylinder solenoid)

INSPECTION PROCEDURE

Note

After replacing the master cylinder solenoid, perform zero point calibration Click here.

PROCEDURE


  1. CHECK PUMP MOTOR OPERATION


    1. Turn the ignition switch off.

    2. Disconnect the A24 skid control ECU (master cylinder solenoid) connector.

    3. Depress the brake pedal more than 40 times.

    4. Turn the ignition switch to ON.

    5. Check pump motor operation.

      OK
      Pump motor operates normally.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

  2. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Reconnect the A24 skid control ECU (master cylinder solenoid) connector.

    3. Turn the ignition switch to ON.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off.

    6. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTC is not output A
      DTC is output (for LHD) B
      DTC is output (for RHD) C

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here