SFI SYSTEM (w/ Electronic Throttle Control System), Diagnostic DTC:P0571

DTC Code DTC Name
P0571 Brake Switch "A" Circuit

DESCRIPTION

The stop light switch has a duplex system (signals STP and ST1-) to memorize the abnormality when the signals of depressing and releasing the brake pedal are detected simultaneously.

Tech Tips

The normal conditions are as shown in the table below.

Signal Brake Pedal Released In Transition Brake Pedal Depressed
STP OFF ON ON
ST1- ON ON OFF
DTC No. DTC Detection Condition Trouble Area
P0571

  • Conditions (a) and (b) continue for 3 seconds or more:


    • (a) Ignition switch ON

    • (b) STP signal off when ST1 signal off

  • (1 trip detection logic)

  • Short in stop light switch signal circuit

  • Stop light switch

  • ECM

WIRING DIAGRAM

A0136U6E03

INSPECTION PROCEDURE

Note


  • After replacing the ECM, perform electronic throttle learning Click here.

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

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 / Stop Light Switch.

    5. Read the value displayed on the tester.

      Standard
      Condition Specified Condition
      Brake pedal depressed STP signal ON
      Brake pedal released STP signal OFF

    NG

    CHECK STOP LIGHT SWITCH INSTALLATION Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

  2. CHECK STOP LIGHT SWITCH INSTALLATION


    1. Check the stop light switch installation Click here.

      OK
      Stop light switch is installed correctly.

    NG

    SECURELY REINSTALL STOP LIGHT SWITCH

    OK

  3. CHECK TERMINAL VOLTAGE (STOP LIGHT SWITCH)

    A0136YOE15
    Text in Illustration
    *a

    Front view of wire harness connector

    (to Stop Light Switch)

    1. Disconnect the stop light switch connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A17-2 - Body ground Always 11 to 14 V
      A17-3 - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT STOP LIGHT SWITCH

    A0138EQE02

    1. 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

    NG

    REPLACE STOP LIGHT SWITCH Click here

    OK

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


    1. Disconnect the A17 stop light switch connector.

    2. Disconnect the B26 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A17-1 - B26-31 (STP) Always Below 1 Ω
      A17-4 - B26-7 (ST1-) Always Below 1 Ω
      A17-1 or B26-31 (STP) - Body ground Always 10 kΩ or higher
      A17-4 or B26-7 (ST1-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here