VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU (master cylinder solenoid) has an open detection circuit, which stores this DTC when detecting an open in the stop light switch input line or the ground line of the stop light switch 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 stop light switch circuit continues for 3 seconds or more.

  • Stop light switch circuit

  • Stop light control relay assembly

  • Stop light control relay circuit

  • Skid control ECU (Master cylinder solenoid)

WIRING DIAGRAM

B001XQQE14

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. READ VALUE USING GTS (STOP LIGHT SW)


    1. Turn the ignition switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS 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 condition observed on the GTS changes according to brake pedal operation.

      OK
      The GTS displays ON and OFF according to brake pedal operation.

    NG

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

  2. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Start the engine.

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

    5. 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

  3. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Turn the ignition switch off.

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

    3. B001WX8E02
      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
      A24-7 (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

  4. CHECK HARNESS AND CONNECTOR (+B/GND TERMINAL)


    1. Turn the ignition switch off.

    2. Disconnect the stop light control relay assembly connector.

    3. B001Y3PE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A39-6 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A39-4 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Turn the ignition switch off.

    2. Disconnect the stop light control relay assembly connector.

    3. B001ZTTE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A39-2 (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

  6. CHECK HARNESS AND CONNECTOR (OUT TERMINAL)


    1. Reconnect the stop light control relay assembly connector.

    2. B001VMSE01
      Text in Illustration
      *a

      Component with harness connected

      (Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A39-8 (OUT) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    NG

    REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY

    OK

  7. RECONFIRM DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Start the engine.

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

    5. 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