ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

The skid control ECU detects the brake operating conditions through a signal transmitted by the stop light switch.

DTC Code DTC Detection Condition Trouble Area
C1425 When the IG1 terminal voltage is between 9.5 and 17.4 V, an open STP terminal circuit continues for 3 seconds or more.
  • STP terminal circuit

  • Stop light control ECU

  • Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM

A00O9YTE03

INSPECTION PROCEDURE

Note

When replacing the brake actuator assembly, 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 the brake pedal operation.

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

    NG
    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 B

    B
    A
  3. INSPECT STOP LIGHT CONTROL ECU


    1. Inspect the stop light control ECU Click here.


    NG
    OK
  4. CHECK TERMINAL VOLTAGE (STP)


    1. Make sure that there is no looseness at the locking parts and connecting parts of the connectors.

    2. Disconnect the A6 skid control ECU connector.

    3. A00O37ME14
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A6-2 (STP) - Body ground Brake pedal depressed 8 to 14 V
      Brake pedal released Below 1.5 V

    NG
    OK
  5. RECONFIRM DTC


    1. Clear the DTC 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 B

    B
    A