VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1251/51

DTC Code DTC Name
C1251/51 Open in Pump Motor Circuit

DESCRIPTION

DTC Code DTC Detection Condition Trouble Area
C1251/51

Either of the following is detected:


  1. Actuator pump motor does not operate properly.

  2. Open in actuator pump motor circuit continues for at least 2 seconds.

  • Brake actuator assembly (Ground circuit)

  • Brake actuator assembly (Motor circuit)

  • Skid control ECU

WIRING DIAGRAM

Refer to DTCs C0273/13, C0274/14 and C1361/91 Click here.

INSPECTION PROCEDURE

Note

When replacing the skid control ECU, perform zero point calibration and store system information Click here.

Tech Tips

When C0273/13, C0274/14 and/or C1361/91 is output together with C1251/51, inspect and repair the trouble areas indicated by C0273/13, C0274/14 and/or C1361/91 first Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ABS MOTOR RELAY)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Select the Active Test mode on the intelligent tester Click here.

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

    4. Check for the operating sound of the ABS motor relay when operating it using the intelligent tester.

      Result
      Result Proceed to
      The operating sound is not heard A
      The operating sound is heard B

    B

    RECONFIRM DTC Click here

    A

  2. INSPECT BRAKE ACTUATOR ASSEMBLY (GND2 TERMINAL)


    1. A015ZUGE03

      Turn the engine switch off.

    2. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    3. Disconnect the brake actuator connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A13-1 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)

    OK

  3. RECONFIRM DTC


    1. Reconnect the brake actuator connector.

    2. Clear the DTCs Click here.

    3. Start the engine.

    4. Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.

    5. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTC (C1251/51) is not output A
      DTC (C1251/51) is output B

      Tech Tips


      • If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU with the engine switch on (IG) and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.

      • If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harness, and fuses of the skid control ECU and/or brake actuator assembly. Make sure that no DTCs are output.

      • If any DTCs are output while jiggling a connector or wire harness of the skid control ECU and/or brake actuator assembly, inspect and repair the connector or wire harness.

      • It is suspected that the DTCs were output due to a bad connection of the connector terminal.


    B

    REPLACE SKID CONTROL ECU Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here