ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Switch Circuit

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) detects the brake operating conditions through a signal transmitted by the stop light switch assembly.

The skid control ECU incorporates a circuit to detect an open circuit. This DTC is output when an open circuit is detected in the stop light signal input line.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1425 Open in Stop Switch Circuit 231 An open stop light switch circuit continues for 10 seconds or more.

  • Wire harness or connector (refer to "Open Detection Area")

  • Stop light switch assembly

  • Skid control ECU (brake booster with master cylinder assembly)

 Electronically controlled brake system DTC

WIRING DIAGRAM

A001O48E08

CAUTION / NOTICE / HINT

Note


  • After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

    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
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  2. READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY)


    1. Select the Data List on the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      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

      		 -

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      Stop Light SW

    2. 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.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (STP TERMINAL) Click here

    OK

  3. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the power switch off.

    3. Turn the power switch on (READY).

    4. Perform a road test.

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1425 is not output. A
      DTC C1425 is output. (for LHD) B
      DTC C1425 is output. (for RHD) C

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

  4. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A005NB5C86
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      Turn the power switch off.

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

      OK
      The connector is securely connected.

    3. Disconnect the A39 skid control ECU (brake booster with master cylinder assembly) connector.

    4. Check both the connector case and the terminals for deformation and corrosion.

      OK
      No deformation or corrosion.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A39-12 (STP) - Body ground

      Stop light switch assembly on

      (Brake pedal depressed)

      		 11 to 14 V
      A39-12 (STP) - Body ground

      Stop light switch assembly off

      (Brake pedal released)

      		 Below 1.5 V
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

  5. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Check the stop light switch assembly.

      Click here

      OK
      The stop light switch assembly is normal.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STP TERMINAL)


    1. A005NB5C86
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      Turn the power switch off.

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

      OK
      The connector is securely connected.

    3. Disconnect the A39 skid control ECU (brake booster with master cylinder assembly) connector.

    4. Check both the connector case and the terminals for deformation and corrosion.

      OK
      No deformation or corrosion.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A39-12 (STP) - Body ground

      Stop light switch assembly on

      (Brake pedal depressed)

      		 11 to 14 V
      A39-12 (STP) - Body ground

      Stop light switch assembly off

      (Brake pedal released)

      		 Below 1.5 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

  7. RECONFIRM DTC


    1. Reconnect the A39 skid control ECU (brake booster with master cylinder assembly) connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the power switch off.

    4. Turn the power switch on (READY).

    5. Perform a road test.

    6. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      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 booster with master cylinder assembly).

      for LHD: Click here

      for RHD: Click here


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here