VEHICLE STABILITY CONTROL 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).

  • ABS NO. 1 fuse

  • Skid control ECU (Master cylinder solenoid)

WIRING DIAGRAM

Refer to DTC C1253 Click here.

CAUTION / NOTICE / HINT

Note


  • After replacing the master cylinder solenoid, perform zero point calibration and store the system information Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (BM1/+BM2 TERMINAL)


    1. Turn the engine switch off.

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

    3. B001B2RE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-2 (+BM1) - Body ground Always 11 to 14 V
      A25-2 (+BM2) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (GND1, GND2 AND GND3 TERMINAL)


    1. B0018RYE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

      Turn the engine switch off.

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

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A24-1 (GND1) - Body ground Always Below 1 Ω
      A24-32 (GND2) - Body ground Always Below 1 Ω
      A25-4 (GND3) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK PUMP MOTOR OPERATION


    1. Turn the engine 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 engine switch on (IG).

    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

  4. RECONFIRM DTC


    1. Turn the engine switch off.

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

    3. Turn the engine switch on (IG).

    4. Clear the DTCs Click here.

    5. Turn the engine 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

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here