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Home >> Toyota >> 2019 >> Highlander Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 27 (Dynamic Radar Cruise Control System (2GR-FE) - Diagnostic Codes & Circuit Tests (Except Hybrid)) >> Dynamic Radar Cruise Control System >> DTC P0571: Brake Switch "A" Circuit [12/2013 - 11/2016] >> Procedure

DTC P0571: Brake Switch "A" Circuit [12/2013 - 11/2016]: Procedure

WARNING: This page is about a different car, the 2016 Toyota Highlander, 2015 Toyota Highlander, and 2014 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK STOP LIGHT OPERATION 
    1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

      OK

      Condition Illumination Condition
      Brake pedal depressed On
      Brake pedal released Off

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

    GO TO LIGHTING SYSTEM (EXT). Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2013 - ] 

    Result:  1

    OK 

    See step  2

  2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH1, STOP LIGHT SWITCH2, BRAKE CANCEL SWITCH) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Radar Cruise / Data List.
    5. Check the Data List for proper functioning of the stop light switch.

      Powertrain > Radar Cruise > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Stop Light Switch 1 Stop light switch signal ON or OFF OK: Brake pedal depressed
      OFF: Brake pedal released      		 -
      Stop Light Switch 2 Stop light switch signal ON or OFF OK: Brake pedal depressed
      OFF: Brake pedal released      		 -
      Brake Cancel Switch Brake cancel signal ON or OFF OK: Brake pedal depressed
      OFF: Brake pedal released      		 -

      Powertrain > Radar Cruise > Data List 

      Tester Display
      Stop Light Switch 1
      Stop Light Switch 2
      Brake Cancel Switch

      OK

      Display changes according to brake pedal operation described in the table.

      Result

      Proceed to
      OK
      NG
    6. Turn the engine switch off.

    Result:  2

    NG 

    See step  8

    Result:  1

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU) 
    1. Disconnect the A54 stop light switch assembly connector.
    2. Disconnect the A47 skid control ECU (brake actuator assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      A54-1 - A47-22 (STP2) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A54-1 or A47-22 (STP2) - Body ground Always 10 kΩ or higher
    4. Reconnect the A47 skid control ECU (brake actuator assembly) connector.
    5. Reconnect the A54 stop light switch assembly connector.

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU AND ECM) 

    Result:  1

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (STOP LP RELAY - SKID CONTROL ECU) 
    1. Remove the STOP LP relay from the engine room relay block and junction block assembly.
    2. Disconnect the A47 skid control ECU (brake actuator assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      Relay terminal 1 - A47-31 (STPO) Always Below 1 Ω
      Relay terminal 4 - A47-22 (STP2) Always Below 1 Ω
      Relay terminal 3 - A47-2 (STP) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      Relay terminal 1 or A47-31 (STPO) - Body ground Always 10 kΩ or higher
      Relay terminal 4 or A47-22 (STP2) - Body ground Always 10 kΩ or higher
      Relay terminal 3 or A47-2 (STP) - Body ground Always 10 kΩ or higher
    4. Reinstall the STOP LP relay to the engine room relay block and junction block assembly.
    5. Reconnect the A47 skid control ECU (brake actuator assembly) connector.

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LP RELAY - SKID CONTROL ECU) 

    Result:  1

    OK 

    See step  5

  5. INSPECT STOP LP RELAY 
    1. Remove the STOP LP relay from the engine room relay block and junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 4 Battery voltage not applied between terminals 1 and 2 Below 1 Ω
      Battery voltage applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Battery voltage applied between terminals 1 and 2 Below 1 Ω
      GTY434739Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 STOP LP Relay
    3. Reinstall the STOP LP relay to the engine room relay block and junction block assembly.

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  COMPONENTS [12/2013 - ] 

    Result:  1

    OK 

    See step  6

  6. REPLACE BRAKE ACTUATOR ASSEMBLY 
    1. Replace the brake actuator assembly.

      Refer to REMOVAL [12/2013 - 11/2016]

    Result: 

    NEXT 

  7. CHECK FOR DTCS (DTC P0571) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [12/2013 - 11/2016]

    4. Perform the following to make sure that the DTC detection conditions are met.

      HINT: 

      If the detection conditions are not met, the malfunction cannot be detected.

      1. Drive the vehicle at a speed for which cruise control operation is possible.
      2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).
      3. Push the cruise control main switch to -SET to activate the dynamic radar cruise control system.
    5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
    6. Check for DTCs.

      Powertrain > Radar Cruise > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      DTC P0571 is output B
    7. Turn the engine switch off.

    Result:  1

    A 

    END 

    Result:  2

    B 

    REPLACE ECM. Refer to  COMPONENTS [12/2013 - 11/2016] 

  8. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - POWER SOURCE) 
    1. Disconnect the A54 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
      A54-2 - Body ground Always 11 to 14 V
      GTY440766Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Stop Light Switch Assembly)
    3. Reconnect the A54 stop light switch assembly connector.

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

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

    Result:  1

    OK 

    See step  9

  9. INSPECT STOP LIGHT SWITCH ASSEMBLY 
    1. Inspect the stop light switch assembly.

      Refer to INSPECTION [12/2013 - 11/2016]

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

    REPLACE STOP LIGHT SWITCH ASSEMBLY. Refer to  COMPONENTS [12/2013 - ] 

    Result:  1

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - ECM) 
    1. Disconnect the A54 stop light switch assembly connector.
    2. Disconnect the A43 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
      A54-3 - A43-36 (ST1-) Always Below 1 Ω
      A54-1 - A43-51 (STP) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A54-3 or A43-36 (ST1-) - Body ground Always 10 kΩ or higher
      A54-1 or A43-51 (STP) - Body ground Always 10 kΩ or higher
    4. Reconnect the A54 stop light switch assembly connector.
    5. Reconnect the A43 ECM connector.

      Result

      Proceed to
      OK
      NG

    Result:  2

    NG 

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

    Result:  1

    OK 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BODY GROUND) 
    1. Disconnect the A54 stop light switch assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A54-1 - Body ground Always 10 kΩ or higher
      A54-3 - Body ground Always 10 kΩ or higher
    3. Reconnect the A54 stop light switch assembly connector.

      Result

      Proceed to
      OK
      NG

    Result:  1

    OK 

    REPLACE ECM. Refer to  COMPONENTS [12/2013 - 11/2016] 

    Result:  2

    NG 

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

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