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 (brake actuator assembly) 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 IG1 terminal voltage is between 9.5 and 17.4 V, an open stop light switch circuit (A to B, A to body ground) continues for 0.3 seconds or more (except restart due to stop and start control*).

  • Stop light switch circuit

  • Skid control ECU (Brake actuator assembly)

  • *: w/ Stop and Start System

WIRING DIAGRAM

C345751E02

CAUTION / NOTICE / HINT

Note:

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

Click here

PROCEDURE

  1. CHECK STOP LIGHT OPERATION

    1. Check that all 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

    CHECK STOP LIGHT CIRCUIT

    OK
  2. CHECK TERMINAL VOLTAGE (STP TERMINAL)

    1. C342353C21

      *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 connectors.

    3. Disconnect the A80 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

      A80-35 (STP) - Body ground

      Stop light switch ON (Brake pedal depressed)

      8 to 14 V

      Stop light switch OFF (Brake pedal released)

      Below 1.5 V

    Result

    Proceed to

    OK

    NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - STOP LIGHT CIRCUIT)

    OK
  3. RECONFIRM DTC

    1. Turn the ignition switch off.

    2. Reconnect the A80 skid control ECU (brake actuator assembly) connector.

    3. Clear the DTCs.

      Click here

    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 > Clear DTCs

    Chassis > ABS/VSC/TRC > Trouble Codes

    Tip:

    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

    Proceed to

    DTC C1425 is not output

    DTC C1425 is output

    DTC C1425 is not output

    USE SIMULATION METHOD TO CHECK

    DTC C1425 is output

    REPLACE BRAKE ACTUATOR ASSEMBLY