СИСТЕМА SFI, 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 (18.63 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

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 (18.63 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.

MONITOR STRATEGY

Required sensors/Components Stop light switch assembly, Vehicle speed sensor
Frequency of operation Continuous

CONFIRMATION DRIVING PATTERN

B007QTNE19

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the intelligent tester on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).

  4. Turn the ignition switch off and wait for at least 30 seconds.

  5. Turn the ignition switch to ON and turn the intelligent tester on [A].

  6. Wait 5 seconds.

  7. Enter the following menus: Powertrain / Engine and ECT / DTC [B].

  8. Read the pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  10. Input the DTC: P0724.

  11. Check the DTC judgment result.

    Intelligent Tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform steps [C] through [E].

  12. Start the engine [C].

  13. Accelerate the vehicle to 30 km/h (19 mph) or more, and then depress the brake pedal and decelerate the vehicle to 3 km/h (1.8 mph) or less [D]. Repeat step [D] 5 times.

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  14. Check the DTC judgment result [E].

WIRING DIAGRAM

Refer to DTC P0504 Click here.

INSPECTION PROCEDURE

Tech Tips

Using the intelligent tester, the Data List item "Stop Light Switch" can be read.

Item

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. CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Check the stop light switch assembly installation.

      OK
      Stop light switch assembly is installed correctly.

    NG

    SECURELY REINSTALL STOP LIGHT SWITCH ASSEMBLY

    OK

  2. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY

    OK

  3. CHECK HARNESS AND CONNECTOR (ECM - BATTERY)

    B007TWGE05
    Text in Illustration
    *a Depressed
    *b 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
      Tester Connection Condition Specified Condition
      B71-36 (STP) - Body ground Brake pedal is depressed 7.5 to 14 V
      Brake pedal is released Below 1.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here