SFI SYSTEM, Diagnostic DTC:P0724

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

DESCRIPTION

The stop light switch assembly is a duplex system that transmits 2 signals: STP and ST1-. These 2 signals are used by the ECM to monitor whether or not the brake system is working properly.

The purpose of this circuit is to prevent the engine from stalling while driving with the lock-up torque converter clutch on when the brakes are suddenly applied.

When the brake pedal is depressed, the stop light 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 vehicle is driven in a GO (30 km/h (18.63 mph) or more) and STOP (less than 3 km/h (1.86 mph)) pattern 5 times (2 trip detection logic).

  • Short in stop light switch signal circuit

  • Stop light switch assembly

  • ECM

WIRING DIAGRAM

Refer to DTC P0504 Click here.

INSPECTION PROCEDURE

Tech Tips


  • Using the intelligent tester to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

  • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

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

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

      OK
      Brake Pedal Display
      Released OFF
      Depressed ON

    NG

    INSPECT STOP LIGHT SWITCH ASSEMBLY Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  2. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

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


    1. A00O6GEE08
      Text in Illustration
      *a Brake Pedal Depressed
      *b Brake Pedal Released
      *c

      Component with harness connected

      (ECM)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G56-18 (STP) - Body ground Brake pedal depressed 11 to 14 V
      Brake pedal released 0 to 3 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here