ELECTRONICALLY CONTROLLED BRAKE 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 circuit occurs between STP terminal circuits A and B for 0.3 seconds or more.

  • Wire harness or connector

  • Stop light switch assembly

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WIRING DIAGRAM

B006GMBE01

CAUTION / NOTICE / HINT

Note


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

    Click here

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

PROCEDURE


  1. READ VALUE USING GTS (STOP LIGHT SW)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    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 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 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 TERMINAL VOLTAGE (STP TERMINAL) Click here

    OK

  2. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Start the engine.

    4. Depress the brake pedal several times to test the stop light circuit.

    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. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

  3. CHECK TERMINAL VOLTAGE (STP TERMINAL)


    1. 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 A9 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A9-35 (STP) - Body ground Stop light switch on (Brake pedal depressed) 8 to 14 V
      A9-35 (STP) - Body ground Stop light switch off (Brake pedal released) Below 1.5 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)