SFI SYSTEM, Diagnostic DTC:P0724

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

DESCRIPTION

The stop light switch is part of 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.

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC.

DTC No. DTC Detection Condition Trouble Area
P0724 Stop light switch remains on even when the vehicle is driven in a GO (30 km/h (18.65 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

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during GO and STOP driving, the ECM interprets this as a fault in the stop light switch. Then the MIL illuminates and the ECM stores the DTC. The vehicle must GO (30 km/h (18.65 mph) or more) and STOP (less than 3 km/h (1.86 mph)) 5 times for 2 driving cycles in order for the DTC to be stored.

WIRING DIAGRAM

Refer to DTC P0504 Click here.

CAUTION / NOTICE / HINT

Tech Tips

Using the GTS to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

Note

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.


  1. Warm up the engine.

  2. Turn the ignition switch off.

  3. Connect the GTS to the DLC3.

  4. Turn the ignition switch to ON.

  5. Turn the GTS on.

  6. Enter the following menus: Powertrain / Engine and ECT / Data List.

  7. According to the display on the GTS, read the Data List.

GTS Display Measurement Item/Range Normal Condition Diagnostic Note
Stop Light Switch Stop light switch status/ON or OFF

  • Brake pedal depressed: ON

  • Brake pedal released: OFF

 -

PROCEDURE


  1. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (ECM - BATTERY)

    A01X25YE01
    Text in Illustration
    *A for LHD
    *B for RHD
    *a Brake Pedal Depressed
    *b Brake Pedal Released
    *c

    Front view of wire harness connector

    (to ECM)

    1. Disconnect the ECM connector.

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      A38-36 (STP) - Body ground Brake pedal depressed 7.5 to 14 V
      A38-36 (STP) - Body ground Brake pedal released Below 1.5 V
      for RHD
      Tester Connection Condition Specified Condition
      A52-36 (STP) - Body ground Brake pedal depressed 7.5 to 14 V
      A52-36 (STP) - Body ground Brake pedal released Below 1.5 V

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR