ECD SYSTEM, Diagnostic DTC:P0571

DTC Code DTC Name
P0571 Stop Light Switch Main Sensor not Plausible

DESCRIPTION

The stop light switch signal is used to detect when the brakes have been applied. The stop light signal voltage is the same as the voltage supplied to the stop light.

DTC No. DTC Detection Condition Trouble Area Possible to Detect
Ignition Switch Engine Run
P0571 Malfunction in the stop light switch

  • Stop light switch

  • Stop light switch circuit

  • ECM

 - -

FAIL-SAFE

DTC No. Fail-safe Operation Fail-safe Deactivation Condition
P0571 - -

WIRING DIAGRAM

A0137Z2E02

INSPECTION PROCEDURE

Tech Tips


  • When DTC P0571 is detected, check the stop light switch by selecting the following menu items on the intelligent tester: Powertrain / Engine and ECT / Data List / Stop Light SW.

  • If the ECM is replaced, variant coding (variant coding indicates the presence of vehicle accessory items, A/C, etc.) should always be performed Click here.

  • Before removing the ECM and the peripheral parts, wait at least 3 minute after turning the ignition switch off (If the cooling fan is operating, remove the ECM and the peripheral parts after the fan stops.).

PROCEDURE


  1. READ VALUE OF INTELLIGENT TESTER (STOP LIGHT SWITCH)


    1. Connect the intelligent tester to the DLC3.

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

    3. Select the following menu items: Powertrain / Engine and ECT / Data List / Stop Light SW.

    4. Read the value.

      OK
      Brake Pedal Specified Condition
      Depressed STP Signal ON
      Released STP Signal OFF

    NG

    CHECK STOP LIGHT SWITCH Click here

    OK

    CHECK FOR INTERMITTENT PROBLEMS

  2. CHECK STOP LIGHT SWITCH


    1. A0136WOE01

      Disconnect the A17 stop light switch connector.

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

      Standard resistance
      Tester Connection Brake Pedal Specified Condition
      3 - 4 Depressed 10 kΩ or higher
      3 - 4 Released Below 1 Ω

    NG

    REPLACE STOP LIGHT SWITCH

    OK

  3. INSPECT STOP LIGHT SWITCH (VOLTAGE)


    1. A0136FOE01

      Disconnect the A17 stop light switch connector.

    2. Turn the ignition switch to the ON position.

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

      Standard voltage
      Tester Connection Specified Condition
      Stop light switch (A17-3) - Body ground 11 to 14 V

    NG

    CHECK AND REPLACE HARNESS AND CONNECTOR (STOP LIGHT SWITCH - BATTERY)

    OK

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


    1. A0136WLE01

      Disconnect the A35 (A36) ECM connector.

    2. Disconnect the A17 stop light switch connector.

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

      Standard resistance (Check for open)
      LHD
      Tester Connection Specified Condition
      BRKR (A35-20) - Stop light switch (A17-4) Below 1 Ω
      RHD
      Tester Connection Specified Condition
      BRKR (A36-20) - Stop light switch (A17-4) Below 1 Ω
      Standard resistance (Check for short)
      LHD
      Tester Connection Specified Condition
      BRKR (A35-20) or Stop light switch (A17-4) - Body ground 10 kΩ or higher
      RHD
      Tester Connection Specified Condition
      BRKR (A36-20) or Stop light switch (A17-4) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM