VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C1425

DTC Code DTC Name
C1425 Open in Stop Light Switch Circuit

DESCRIPTION

The master cylinder solenoid (skid control ECU) inputs stop light switch signals and the condition of brake operation.

The skid control ECU has an open detection circuit, which outputs this DTC when detecting an open in the stop light input line or the ground line of the stop light circuit with the stop light switch off (brake pedal not depressed).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1425

Open in Stop Light Switch Circuit

When the IG1 terminal voltage is between 9.5 and 17.4 V and the skid control ECU STPO terminal output is off, an open in the stop light switch circuit continues for 3 seconds or more.

  • Stop light switch circuit

  • Stop light control relay

  • Stop light control relay circuit

  • Master cylinder solenoid (Skid control ECU)

WIRING DIAGRAM

C222520E04

CAUTION / NOTICE / HINT

Note:

When replacing the master cylinder solenoid, perform calibration (Click here).

PROCEDURE

  1. READ VALUE USING INTELLIGENT TESTER (STOP LIGHT SW)

    1. Turn the engine switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      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

      -

    6. Check that the stop light switch condition observed on the intelligent tester changes according to brake pedal operation.

      OK

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

      Result

      Result

      OK

      NG
    NG

    CHECK TERMINAL VOLTAGE AND RESISTANCE (+B, GND)Click here

    OK

  2. RECONFIRM DTC

    1. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    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

      Chassis > ABS/VSC/TRC > Trouble Codes

    A

    USE SIMULATION METHOD TO CHECK

    Click here

    B

    REPLACE MASTER CYLINDER SOLENOID

    Click here

  3. CHECK TERMINAL VOLTAGE AND RESISTANCE (+B, GND)

    1. Disconnect the A6 stop light control relay connector.

    2. C206543C01

      *a

      Front view of wire harness connector

      (to Stop Light Control Relay)

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A6-6 (+B) - Body ground

      Always

      11 to 14 V

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A6-4 (GND) - Body ground

      Always

      Below 1 Ω

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK TERMINAL VOLTAGE (STP)

    1. Disconnect the A6 stop light control relay connector.

    2. C206543C02

      *a

      Front view of wire harness connector

      (to Stop Light Control Relay)

      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

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK TERMINAL VOLTAGE (OUT)

    1. Reconnect the A6 stop light control relay connector.

    2. E205929C01

      *a

      Component with harness connected

      (Stop Light Control Relay)

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A6-8 (OUT) - Body ground

      Brake pedal depressed

      8 to 14 V

      Brake pedal released

      Below 1.5 V

      Result

      Result

      OK

      NG
    NG

    REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY

    Click here

    OK

  6. CHECK TERMINAL VOLTAGE (STP)

    1. Disconnect the A7 skid control ECU connector.

    2. C214161C05

      *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

      A7-7 (STP) - Body ground

      Brake pedal depressed

      8 to 14 V

      Brake pedal released

      Below 1.5 V

      Result

      Result

      OK

      NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. RECONFIRM DTC

    1. Clear the DTCs.

      Click here

      Chassis > ABS/VSC/TRC > Clear DTCs

    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

      Chassis > ABS/VSC/TRC > Trouble Codes

    A

    USE SIMULATION METHOD TO CHECK

    Click here

    B

    REPLACE MASTER CYLINDER SOLENOID

    Click here