ANTI-LOCK BRAKE 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 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.

Detection Item

DTC Detection Condition

Trouble Area

C1425

Open in Stop Light Switch Circuit

An open in the stop light switch input line continues for 3 seconds or more.

  • Wire harness or connector

  • Stop light switch assembly

  • Stop light control ECU assembly

  • Skid control ECU (brake actuator assembly)

WIRING DIAGRAM

C357862E03

CAUTION / NOTICE / HINT

Note:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

  1. CHECK STOP LIGHT SWITCH 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 ASSEMBLYClick here

    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 using 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

      ON or OFF

      ON: Brake pedal depressed

      OFF: Brake pedal released

      -

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Stop Light SW

    4. Check that the stop light switch 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. Turn the ignition switch off.

    2. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    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

      Chassis > ABS/VSC/TRC > Trouble Codes

      Result

      Result

      Proceed to

      DTC C1425 is not output.

      A

      DTC C1425 is output.

      B
      Tip:

      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

    A

    USE SIMULATION METHOD TO CHECK

    Click hereClick hereClick here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here

  4. CHECK HARNESS AND CONNECTOR (STP TERMINAL)

    1. C278421C03

      *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 A120 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

      A120-30 (STP) - Body ground

      Stop light switch ON (Brake pedal depressed)

      11 to 14 V*

      A120-30 (STP) - Body ground

      Stop light switch OFF (Brake pedal released)

      Below 1.5 V
      Tip:

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

      Result

      Proceed to

      OK

      NG
      Tip:

      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

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here

    NG

    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. INSPECT STOP LIGHT CONTROL ECU ASSEMBLY

    1. Check the stop light control ECU assembly.

      Click here

      OK

      The stop light control ECU assembly is normal.

    Result

    Result

    Proceed to

    OK

    A

    NG (+B, GND, STP terminal)

    B

    NG (OUT terminal)

    C
    B

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    C

    REPLACE STOP LIGHT CONTROL ECU ASSEMBLY

    Click here

    A

  7. CHECK HARNESS AND CONNECTOR (STP TERMINAL)

    1. C278421C03

      *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 A120 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

      A120-30 (STP) - Body ground

      Stop light switch ON (Brake pedal depressed)

      11 to 14 V*

      A120-30 (STP) - Body ground

      Stop light switch OFF (Brake pedal released)

      Below 1.5 V
      Tip:

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

      Result

      Proceed to

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

    OK

  8. RECONFIRM DTC

    1. Reconnect the A120 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    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

      Chassis > ABS/VSC/TRC > Trouble Codes

      Result

      Result

      Proceed to

      DTC C1425 is not output.

      A

      DTC C1425 is output.

      B
      Tip:

      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

    A

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT)

    Click hereClick here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY

    Click hereClick hereClick here