VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1426

DTC Code DTC Name
C1426 Stop Light Switch OFF Stuck Malfunction

DESCRIPTION

The skid control ECU (master cylinder solenoid) inputs the stop light signal and brake operation condition. When the brake pedal is depressed and the stop light switch signal is not input, C1426 is output.

DTC Code DTC Detection Condition Trouble Area
C1426

When both of the following conditions are met:


  • After the vehicle reaches 35 km/h or more, the PMC terminal voltage is continuously 0.86 V or higher for 1 second or more at a vehicle speed of 3 km/h or more.

  • The stop light switch signal is not input for 5 seconds or more with the PMC terminal voltage at 0.86 V or higher while the IG terminal voltage is 9.5 V or higher and the vehicle speed is 3 km/h or less for a period of less than 0.6 seconds.

  • Wire harness or connector

  • STOP fuse

  • Stop light switch assembly

  • Skid Control ECU (Master cylinder solenoid)

WIRING DIAGRAM

Refer to DTC C1425 Click here.

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (master cylinder solenoid), perform zero point calibration and store system information. Click here.

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

PROCEDURE


  1. CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION


    1. Turn the engine switch off.

    2. Check the brake pedal height and stop light switch assembly installation (for LHD: See , for RHD: Click here.

      OK
      The brake pedal height and stop light switch installation are normal.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    ADJUST BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION Click here

    C

    ADJUST BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION Click here

    A

  2. CHECK STOP LIGHT OPERATION


    1. Check that the all stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

      OK
      Condition Illumination Condition
      Brake pedal depressed On
      Brake pedal released Off

    NG

    INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  3. READ VALUE USING GTS (STOP LIGHT SW)


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch 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 display observed on the GTS changes according to brake pedal operation.

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

    NG

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

  4. RECONFIRM DTC


    1. Turn the engine switch off.

    2. Clear the DTCs Click here.

    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 C1426 is not output A
      DTC C1426 is output (for LHD) B
      DTC C1426 is output (for RHD) C

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step.


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPLACE MASTER CYLINDER SOLENOID Click here

  5. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Check the stop light switch assembly Click here.

      OK
      The stop light switch assembly is normal.

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Turn the engine switch off.

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

    3. B0018D1E01
      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 (STP CIRCUIT)

    OK

  7. RECONFIRM DTC


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

    2. Clear the DTCs Click here.

    3. Turn the engine switch off.

    4. Start the engine.

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

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

      Result
      Result Proceed to
      DTC C1426 is not output A
      DTC C1426 is output B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here

  8. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. Turn the engine switch off.

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

    3. B0018D1E01
      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
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE MASTER CYLINDER SOLENOID Click here

    B

    REPLACE MASTER CYLINDER SOLENOID Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)