SFI SYSTEM, Diagnostic DTC:P0571

DTC Code DTC Name
P0571 Brake Switch "A" Circuit

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0571 Brake Switch "A" Circuit

DTC Detection Condition


    Enable Criteria (1)

  • Engine switch on (IG)

  • Accelerator pedal position 0.684% or higher

  • Vehicle speed 10 km/h or more

  • Brake pressure error status signal received OK.

  • Brake pressure less than 0 MPa


    Enable Criteria (2)

  • Engine switch on (IG)

  • Vehicle speed 0 km/h or higher

  • Brake pressure error status signal received OK.

  • Brake pressure 1.2 MPa or more


    Malfunction Criteria (1)

  • Stop light switch on (Brake active)


    Malfunction Criteria (2)

  • Stop light switch off (Brake inactive)


    Malfunction Criteria (3)

  • CAN message containing brake switch signal error


    Diagnostic Mask

  • The service light will be illuminated for 30 seconds at the point the fault occurs, and then illuminate for 30 seconds after engine start if the fault is present


    Monitor

  • Continuous


    Potential failure modes

  • Brake switch wiring open circuit or shorted

  • Brake switch fault

  • Open or short in stop light switch signal circuit

  • Stop light switch assembly

  • ECM

 Comes on DTC stored

WIRING DIAGRAM

B00469BE02

CAUTION / NOTICE / HINT

Tech Tips


  • Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. 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.

  • STP signal conditions can be checked using the GTS.


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Data List / All Data / Stop Light Switch and ST1.

    5. Check the STP signal when the brake pedal is depressed and released.

Brake Pedal Operation Stop Light Switch ST1
Depressed ON ON
Released OFF OFF

PROCEDURE


  1. READ VALUE USING GTS (STOP LIGHT SWITCH AND ST1)


    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 / Data List / Stop Light Switch and ST1.

    5. Read the value displayed on the GTS.

      Standard
      Condition Specified Condition
      Brake pedal depressed ON
      Brake pedal released OFF
      Result
      Proceed to
      OK
      NG

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

  2. CHECK STOP LAMP SWITCH ASSEMBLY INSTALLATION


    1. Check the stop light switch assembly installation.

      Click here

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

    NG

    SECURELY REINSTALL STOP LAMP SWITCH ASSEMBLY Click here

    OK

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)

    B0045VBC08
    *a

    Front view of wire harness connector

    (to Stop Light Switch Assembly)

    1. Disconnect the stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A83-7 (B) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  4. CHECK TERMINAL VOLTAGE (POWER SOURCE OF STOP LIGHT SWITCH ASSEMBLY)

    B0045VBC09
    *a

    Front view of wire harness connector

    (to Stop Light Switch Assembly)

    1. Disconnect the stop light switch assembly connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A83-6 (B) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK TERMINAL VOLTAGE (POWER SOURCE OF INSTRUMENT PANEL JUNCTION BLOCK ASSEMVBLY) Click here

    OK

  5. INSPECT STOP LAMP SWITCH ASSEMBLY


    1. Inspect the stop light switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND)


    1. Disconnect the A83 stop light switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-2 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK TERMINAL VOLTAGE (ST- VOLTAGE)


    1. Disconnect the ECM connector.

      B004880C02
      *a Brake Pedal Depressed *b Brake Pedal Released
      *c

      Front view of wire harness connector

      (to ECM)

      		 - -

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Brake Pedal Operation Specified Condition
      A116-40 (ST1-) - Body ground Released 7.5 to 14 V
      Depressed Below 1.5 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM) Click here

    OK

  8. CHECK TERMINAL VOLTAGE (STP VOLTAGE)


    1. Disconnect the network gateway ECU connector.

      B00466EC02
      *a Brake Pedal Depressed *b Brake Pedal Released
      *c

      Front view of wire harness connector

      (to ECM)

      		 - -

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Brake Pedal Operation Specified Condition
      A118-9 (STP) - Body ground Released Below 1.5 V
      Depressed 7.5 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - NETWORK GATEWAY ECU) Click here

    OK

  9. CHECK WHETHER DTC OUTPUT RECURS


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Clear the DTCs.

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

    6. Turn the engine switch on (IG).

    7. Turn the GTS on.

    8. Start the engine.

    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    10. Input the DTC: P0571.

    11. Check the DTC judgment result.

      Result
      Result Proceed to

      NORMAL

      (DTCs are not output)

      		 A

      ABNORMAL

      (DTC P0571 is output)

      		 B

    A

    CHECK FOR INTERMITTENT PROBLEMS Click here

    B

    REPLACE ECM Click here

  10. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - NETWORK GATEWAY ECU)


    1. Disconnect the A83 stop light switch assembly connector.

    2. Disconnect the A118 network gateway ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-3 (L) - A118-4 (STP) Always Below 1 Ω
      A83-3 (L) or A118-4 (STP) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NETWORK GATEWAY ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. Disconnect the A83 stop light switch assembly connector.

    2. Disconnect the A116 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A83-5 (L) - A116-40 (ST-) Always Below 1 Ω
      A83-5 (L) or A116-40 (ST-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  12. CHECK TERMINAL VOLTAGE (POWER SOURCE OF INSTRUMENT PANEL JUNCTION BLOCK ASSEMVBLY)


    1. B0046Q1C01
      *a

      Front view of wire harness connector

      (to Instrument Panel Junction Block Assembly)

      		 *b for LHD
      *c for RHD - -

      Disconnect the Instrument Panel Junction Block Assembly connector.

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      3E-1 - Body ground Always 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition
      3F-1 - Body ground Always 11 to 14 V
      Result
      Result
      OK
      NG

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR