VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU receives stop light switch signals and uses them to determine whether or not the brakes are applied.

The skid control ECU has a detection circuit that it uses to detect an open in the stop light input line.

If the skid control ECU detects an open in this circuit, it will store this DTC.

DTC No. DTC Detection Condition Trouble Area
C1425 An open in the stop light switch input line continues for 3 seconds or more.

  • STOP fuse

  • Stop light switch assembly

  • Stop light switch circuit

  • Skid control ECU (Brake actuator assembly)

WIRING DIAGRAM

Refer to DTC C1249 Click here.

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK STOP LIGHT OPERATION


    1. Check that the 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

  2. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SWITCH ASSEMBLY)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Select the Data List using the intelligent tester Click here.

      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

      		 -

    4. 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

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

  3. RECONFIRM DTC


    1. Turn the ignition switch off.

    2. Clear the DTCs Click here.

    3. Turn the ignition 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 C1425 is not output. A
      DTC C1425 is output. B

      Tech Tips

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


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  4. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Check the stop light switch assembly Click here for TMC, TMMR made or Click here for TMMK made).

      OK
      The stop light switch assembly is normal.

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. B000L6NE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Reconnect the stop light switch assembly connector.

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

    3. Disconnect the skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A49-30 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 11 to 14 V*
      A49-30 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

      Tech Tips

      *: The standard voltage value varies depending on the +BS terminal voltage value. The standard voltage is 85% of the +BS terminal voltage.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

  6. RECONFIRM DTC


    1. Reconnect the skid control ECU connector.

    2. Clear the DTCs Click here.

    3. Turn the ignition 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 C1425 is not output. A
      DTC C1425 is output. B

      Tech Tips


      • If the lighting system is normal but the DTC is still output, replace the skid control ECU (brake actuator assembly) Click here.

      • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts Click here.


    B

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  7. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. B000L6NE13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

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

    3. Disconnect the skid control ECU connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A49-30 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 11 to 14 V*
      A49-30 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V

      Tech Tips

      *: The standard voltage value varies depending on the +BS terminal voltage value. The standard voltage is 85% of the +BS terminal voltage.

      Tech Tips

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


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here