SFI SYSTEM, Diagnostic DTC:P0724

DTC Code DTC Name
P0724 Brake Switch "B" Circuit High

DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling, while driving in lock-up condition, when brakes are suddenly applied.

When the brake pedal is depressed, this switch sends a signal to the ECM. Then the ECM cancels the operation of the lock-up clutch while braking is in progress.

DTC No. DTC Detection Condition Trouble Area
P0724

The stop light switch remains ON even when the vehicle repeats 5 cycles of STOP (less than 1.86 mph [3 km/h]) and GO (18.65 mph [30 km/h] or more)

(2 trip detection logic)

  • Short in stop light switch signal circuit

  • Stop light switch

  • ECM

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains ON. When the stop light switch remains ON during "stop and go" driving, the ECM interprets this as a fault in the stop light switch and the MIL comes on and the ECM stores the DTC. The vehicle must stop (less than 1.86 mph [3 km/h]) and go (18.65 mph [30 km/h] or more) 5 times during 2 driving cycles, in order to detect a malfunction.

WIRING DIAGRAM

Refer to DTC P0504 Click here.

CAUTION / NOTICE / HINT

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) and turn the tester ON.

    3. Enter the following menus: Powertrain / Engine / Data List / Stop Light Switch.

    4. Read the values displayed on the tester.

      OK
      Item Measurement Item: Range (display) Normal Condition
      Stop Light Switch

      Stop light switch status:

      ON or OFF

      • ON: Brake pedal is depressed

      • OFF: Brake pedal is released

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  2. CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Check the stop light switch assembly installation Click here.

      OK
      Stop light switch assembly is installed correctly.

    NG

    SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY

    OK

  3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM)

    A001AZXE02
    *1 Front view of wire harness connector: (to Stop Light Switch)
    *2 ECM Connector

    1. Disconnect the A79 stop light switch connector.

    2. Disconnect the A14 ECM connector.

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      A79-2 (L) - A14-13 (STP) Always Below 1 Ω
      A79-4 (L) - A14-12 (ST1-) Always
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      A79-2 (L) or A14-13 (STP) - Body ground Always 10 kΩ or higher
      A79-4 (L) or A14-12 (ST1-) - Body ground Always

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly Click here.


    OK

    REPLACE ECM Click here

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here