ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1251

DTC Code DTC Name
C1251 Open in Pump Motor Circuit

DESCRIPTION

The ABS motor relay supplies power to the ABS pump motor. While the ABS is activated, the ECU turns the motor relay on and operates the ABS pump motor.

If the voltage supplied to the motor relay (BM) is below the DTC's detection threshold due to low voltage from the battery or generator, the DTC may be stored.

DTC No. DTC Detection Condition Trouble Area
C1251

When any of following conditions detected with normal battery voltage (11 V or more):


  1. Open in pump motor power supply circuit or open in motor power supply circuit ground

  2. Motor stuck mechanically and does not operate

  3. Motor coil shorted and overcurrent flows

  • ABS NO. 1 fuse

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

B00466IE05

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Clear the DTC Click here.

    5. Enter the following menu: Chassis / ABS/VSC/TRC / Active Test.

    6. In accordance with the display on the GTS, perform the Active Test.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Motor Relay Turns ABS motor relay ON or OFF Operating sound of motor can be heard

    7. Check the operation sound of the ABS motor when operating it with the GTS.

      OK
      The operation sound of the ABS motor can be heard.

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (BATTERY - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY) - BODY GROUND)


    1. B00455CC01
      *A for RHD
      *B for LHD
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage (for RHD)
      Tester Connection Condition Specified Condition
      A78-14 (+BM) - Body ground Always 11 to 14 V
      Standard Voltage (for LHD)
      Tester Connection Condition Specified Condition
      A79-14 (+BM) - Body ground Always 11 to 14 V

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

      Standard Resistance (for RHD)
      Tester Connection Condition Specified Condition
      A78-13 (GND1) - Body ground Always Below 1 Ω
      A78-26 (GND2) - Body ground Always Below 1 Ω
      Standard Resistance (for LHD)
      Tester Connection Condition Specified Condition
      A79-13 (GND1) - Body ground Always Below 1 Ω
      A79-26 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. RECONFIRM DTC


    1. Clear the DTC Click here.

    2. Start the engine.

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

      Result Proceed to
      DTC C1251 is not output A
      DTC C1251 is output (for LHD) B
      DTC C1251 is output (for RHD) C

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    C

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here