AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0724

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

DESCRIPTION

The purpose of this circuit is to prevent the engine from stalling when the brakes are suddenly applied while driving in lock-up.

When the brake pedal is depressed, this switch sends a signal to the TCM. Then the TCM cancels the operation of the lock-up clutch while braking is in progress.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0724 Brake Switch "B" Circuit High The stop light switch remains on even when the vehicle is driven in a STOP (less than 3 km/h (2 mph)) and GO (30 km/h (19 mph) or more) pattern 5 times (2-trip detection logic).

  • Short in stop light switch signal circuit

  • Stop light switch

  • TCM

 Comes on DTC stored

MONITOR DESCRIPTION

This DTC indicates that the stop light switch remains on. When the stop light switch remains on during "stop and go" driving, the TCM interprets this as a fault in the stop light switch, illuminates the MIL and stores the DTC. The vehicle must stop (less than 3 km/h (2 mph)) and go (30 km/h (19 mph) or more) five times for two consecutive driving cycles in order for this DTC to be stored.

WIRING DIAGRAM

A01QRHGE02
*a FL MAIN
*b STOP
*c Stop Light Switch
*d Battery

CAUTION / NOTICE / HINT

Note

Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

Click here


  1. DATA LIST

    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 / ECT / Data List.

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


      Powertrain > ECT > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Switch Stop light switch status ON or OFF

      • ON: Brake pedal depressed

      • OFF: Brake pedal released

      		 -

      Powertrain > ECT > Data List
      Tester Display
      Stop Light Switch

PROCEDURE


  1. CHECK STOP LIGHT SWITCH ASSEMBLY INSTALLATION


    1. Check the stop light switch assembly installation.

      Click here

      OK
      Stop light switch assembly is installed correctly.
      Result
      Proceed to
      OK
      NG

    NG

    SECURELY INSTALL OR REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - TCM)


    1. Disconnect the A77 stop light switch assembly connector.

    2. Disconnect the B79 TCM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A77-3 (L) - B79-12 (STP) Brake pedal depressed Below 1 Ω
      A77-3 (L) or B79-12 (STP) - Body ground Brake pedal released 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE TCM Click here

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here