SFI 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 while driving in the lock-up condition when the brakes are suddenly applied.

When the brake pedal is depressed, this 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

Stop light switch remains ON even when vehicle is driven in GO (30 km/h (19 mph) or more) and STOP (less than 3 km/h (2 mph)) pattern 5 times

(2 trip detection logic)

  • Short in stop light switch signal circuit

  • Stop light switch

  • ECM

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


  • The following procedure is based on the premise that the stop lights are functioning normally. If the stop lights are not functioning, proceed to Stop Light Circuit Click here.

  • 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 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.

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 with the brake pedal 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. A011984E12

      Remove the stop light switch.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 2 Switch pin not pushed Below 1 Ω
      Switch pin pushed 10 kΩ or higher
      3 - 4 Switch pin not pushed 10 kΩ or higher
      Switch pin pushed Below 1 Ω

    3. Reinstall the stop light switch.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

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


    1. Disconnect the stop light switch connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A18-36 (STP) - A27-1 Always Below 1 Ω
      A18-35 (ST1-) - A27-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A18-36 (STP) or A27-1 - Body ground Always 10 kΩ or higher
      A18-35 (ST1-) or A27-4 - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the stop light switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here