VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1425/49

DTC Code DTC Name
C1425/49 Open in Stop Switch Circuit

DESCRIPTION

The skid control ECU receives stop light switch assembly 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 Code DTC Detection Condition Trouble Area
C1425 An open in the stop light switch assembly 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

    CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL) Click here

    OK

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    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 assembly / ON or OFF

      ON: Brake pedal depressed

      OFF: Brake pedal released

      		 -

    4. Check that the stop light switch assembly 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 engine switch off.

    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 C1425 is not output. A
      DTC C1425 is output. B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A01CG6HE36

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

    2. Disconnect the stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A1-2 - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  5. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. A01CD76E04

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 2 Switch pin free Below 1 Ω
      1 - 2 Switch pin pushed in 10 kΩ or higher

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A01CFJZE89

      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 brake actuator assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A10-30 (STP) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V
      A10-30 (STP) - Body ground Stop light switch assembly OFF (Brake pedal released) Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

  7. RECONFIRM DTC


    1. Reconnect the skid control ECU 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 C1425 is not output. A
      DTC C1425 is output. B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here

  8. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A01CFJZE89

      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 brake actuator assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A10-30 (STP) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V
      A10-30 (STP) - Body ground Stop light switch assembly OFF (Brake pedal released) Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here