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) detects the brake operating conditions through a signal transmitted by the stop light switch.

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 DTC Detection Condition Trouble Area Note
C1425 Open in Stop Light Switch Circuit When voltage at terminal +BS is 9.5 to 17.4 V, open in the stop light switch input line continues for 0.3 seconds or more (except restart due to stop and start control).

  • Wire harness or connector

  • Skid control ECU (brake actuator assembly)

 -

WIRING DIAGRAM

Refer to DTC C1380.

Click here

CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

Click here

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. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. 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

    4. Check that the stop light switch assembly condition 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 TERMINAL VOLTAGE (STP TERMINAL) Click here

    OK

  3. RECONFIRM DTC


    1. Turn the engine switch off.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the engine 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 recorded.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes

      Tech Tips

      If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step.

      Click here

      Result
      Result Proceed to
      DTC C1425 is not output. A
      DTC C1425 is output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

  4. CHECK TERMINAL VOLTAGE (STP TERMINAL)


    1. B006O10C55
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the engine switch off.

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

    3. Disconnect the A50 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
      A50-35 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A50-35 (STP) - Body ground Stop light switch OFF (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - STOP LIGHT 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 TERMINAL VOLTAGE (STP TERMINAL)


    1. B006O10C55
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the engine switch off.

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

    3. Disconnect the A50 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
      A50-35 (STP) - Body ground Stop light switch ON (Brake pedal depressed) 8 to 14 V
      A50-35 (STP) - Body ground Stop light switch 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 A50 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the engine 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

      Tech Tips


      • If the lighting system is normal but the DTC is still output, replace the skid control ECU (brake actuator assembly).

        Click here

      • 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 here

    B

    INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) Click here