VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

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

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

If the skid control ECU (brake actuator assembly) 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 assembly input line continues for 3 seconds or more.
  • Wire harness or connector

  • Stop light switch assembly

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

A004PJ8E02

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration sensor zero point calibration Click here.

  • Inspect the fuses for circuits related to this system before performing the following 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
    OK
  2. READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Select the Data List on the GTS 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 GTS changes according to brake pedal operation.

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

    NG
    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 Click here.


    A
    B
  4. CHECK TERMINAL VOLTAGE (STP TERMINAL)


    1. A004NP6E01
      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 A84 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A84-6 (STP) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V*
      A84-6 (STP) - Body ground Stop light switch assembly 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.


    OK
    NG
  5. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Check the stop light switch assembly Click here.

      OK
      The stop light switch assembly is normal.

    NG
    OK
  6. CHECK TERMINAL VOLTAGE (STP AND STP2 TERMINAL)


    1. A004RLQE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

    2. Disconnect the A84 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A84-6 (STP) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V*
      A84-6 (STP) - Body ground Stop light switch assembly OFF (Brake pedal released) Below 1.5 V
      A84-24 (STP) - Body ground Stop light switch assembly ON (Brake pedal depressed) 11 to 14 V*
      A84-24 (STP) - Body ground Stop light switch assembly 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
    OK
  7. RECONFIRM DTC


    1. Reconnect the A84 skid control ECU (brake actuator assembly) 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.


    A
    B