VEHICLE STABILITY CONTROL SYSTEM (for Hydraulic Brake Booster), Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU (master cylinder solenoid) inputs stop light switch signals and the condition of brake operation.

The skid control ECU (master cylinder solenoid) has an open detection circuit, which outputs this DTC when detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

DTC Code DTC Detection Condition Trouble Area
C1425 When the IG1 terminal voltage is between 9.5 and 17.4 V and the skid control ECU STPO terminal output is off, an open in the STP terminal circuit continues for 3 seconds or more.

  • STP terminal circuit

  • Stop light control ECU

  • Stop light control ECU circuit

  • Skid control ECU (Master cylinder solenoid)

WIRING DIAGRAM

A01DOAQE01

INSPECTION PROCEDURE

Note

When replacing the skid control ECU (master cylinder solenoid), perform calibration Click here.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SW)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light SW Stop light switch / ON or OFF

      ON: Brake pedal depressed

      OFF: Brake pedal released

      		 -

    6. Check that the stop light switch display observed on the intelligent tester changes according to brake pedal operation.

      OK
      The intelligent tester displays ON or OFF according to brake pedal operation.

    NG

    INSPECT STOP LIGHT CONTROL ECU ASSEMBLY Click here

    OK

  2. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Start the engine.

    3. Depress the brake pedal several times to test the stop light circuit.

    4. 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

    USE SIMULATION METHOD TO CHECK Click here

  3. INSPECT STOP LIGHT CONTROL ECU ASSEMBLY


    1. Inspect the stop light control ECU assembly Click here.


    NG

    REPLACE STOP LIGHT CONTROL ECU Click here

    OK

  4. CHECK TERMINAL VOLTAGE (STP)


    1. Disconnect the A7 skid control ECU (master cylinder solenoid) connector.

    2. A01DRS6E31
      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
      A7-7 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Start the engine.

    3. Depress the brake pedal several times to test the stop light circuit.

    4. 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

    USE SIMULATION METHOD TO CHECK Click here