SFI SYSTEM, Diagnostic DTC:P0724

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

DESCRIPTION

The stop light switch assembly is part of a duplex system that transmits two signals: STP and ST1-. These two signals are used by the ECM to monitor whether or not the brake system is working properly. This DTC indicates that the stop light switch assembly remains on. When the stop light switch assembly remains on during "STOP and GO" driving, the ECM interprets this as a fault in the stop light switch assembly. Then the ECM illuminates the MIL and stores the DTC.

DTC No. DTC Detection Condition Trouble Area
P0724 The stop light switch assembly remains on even when the vehicle repeats 5 cycles of STOP (less than 3 km/h [1.86 mph]) and GO (30 km/h [18.65 mph] or more) (2 trip detection logic).

  • Short in stop light switch signal circuit

  • Stop light switch assembly

  • ECM

MONITOR DESCRIPTION

This DTC indicates that the stop light switch assembly remains on. When the stop light switch assembly remains on during "STOP and GO" driving, the ECM interprets this as a fault in the stop light switch assembly. The ECM turns on MIL and stores the DTC. The vehicle must STOP (less than 3 km/h (1.86 mph)) and GO (30 km/h (18.65 mph) 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


  • Using the GTS, the Data List item "Stop Light Switch" and "ST1" can be read Click here.

  • Read freeze frame data using the GTS. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 GTS (STOP LIGHT SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine and ECT / Data List / Stop Light Switch.

    5. Read the value displayed on the GTS when the brake pedal is depressed and released.

      OK
      Item Measurement Item/Range Normal Condition
      Stop Light Switch

      Stop light switch assembly status/

      ON or OFF

      • ON: Brake pedal depressed

      • OFF: Brake pedal 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 Click here

    OK

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


    1. Disconnect the stop light switch assembly connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A73-2 (L) - A38-36 (STP) Always Below 1 Ω
      A73-2 (L) or A38-36 (STP) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A73-2 (L) - A52-36 (STP) Always Below 1 Ω
      A73-2 (L) or A52-36 (STP) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM)

    OK

  4. CHECK STOP LIGHT SWITCH ASSEMBLY


    1. Check the stop light switch assembly Click here.


    OK

    REPLACE ECM Click here

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here