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.

MONITOR STRATEGY

Required Sensors/Components (Main) Stop light switch assembly
Required Sensors/Components (Related) Speed sensor
Frequency of Operation Continuous

CONFIRMATION DRIVING PATTERN

A01FFIKE34

  1. Connect the GTS to the DLC3.

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

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

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

  5. Turn the engine switch on (IG) and turn the GTS on [A].

  6. Wait 5 seconds.

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

  8. Read 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.

    GTS 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 (18.65 mph) or more, depress the brake pedal and decelerate the vehicle to 3 km/h (1.86 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

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips


  • 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.

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

PROCEDURE


  1. READ VALUE USING GTS (STOP LIGHT SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Read the value displayed on the GTS.

      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

    NG

    INSPECT STOP LIGHT SWITCH ASSEMBLY INSTALLATION Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  2. INSPECT STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Inspect 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 (ECM - STOP LIGHT SWITCH ASSEMBLY)


    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
      Tester Connection Condition Specified Condition
      A5-2 (L) - A19-13 (STP) Always Below 1 Ω
      A5-2 (L) or A19-13 (STP) - Body ground Always 10 kΩ or higher

    NG

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

    OK

  4. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly Click here


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

    REPLACE ECM Click here