DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:P0571

DTC Code DTC Name
P0571 Brake Switch "A" Circuit

DESCRIPTION

  • When the brake pedal is depressed, the stop light switch assembly sends a signal to the ECM. When the ECM receives this signal, it cancels the dynamic radar cruise control. The fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is applied, voltage is normally applied to terminal STP of the ECM through the STOP fuse and the stop light switch assembly, and the ECM turns the dynamic radar cruise control system off.

  • The ECM receives the brake demand signal from the driving support ECU assembly and transmits it to the skid control ECU (brake actuator assembly). The skid control ECU (brake actuator assembly) receives a signal from the ECM and operates the skid control ECU (brake actuator assembly). The skid control ECU (brake actuator assembly) operates the brake actuator assembly and at the same time illuminates the stop light by operating the stop light control ECU assembly*1 or STOP LP relay (stop light control relay)*2.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

P0571

Brake Switch "A" Circuit

  • When the ignition switch is turned ON and the dynamic radar cruise control system is operating, voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for approximately 0.5 seconds or more.

  • While the dynamic radar cruise control system is operating (vehicle-to-vehicle distance control mode), the ECM detects the stop light control ECU assembly error signal from the skid control ECU (brake actuator assembly) for approximately 0.2 seconds or more*1.

  • While the dynamic radar cruise control system is operating (vehicle-to-vehicle distance control mode), the ECM detects the STOP LP Relay (stop light control relay) signal from the skid control ECU (brake actuator assembly) for approximately 0.2 seconds or more*2.

  • Stop light switch assembly

  • Stop light switch circuit

  • ECM

  • Stop light control ECU assembly*1

  • STOP LP relay (stop light control relay)*2

  • Stop light control ECU assembly circuit*1

  • STOP LP relay(Stop light control relay) circuit*2

  • Skid control ECU (brake actuator assembly)

  • ECM

  • *1: for LED Type Stop Light

  • *2: for Bulb Type Stop Light

WIRING DIAGRAM

E288572E34
E288572E35
E288572E38
E288572E37
E337398E06

CAUTION / NOTICE / HINT

Note:

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

  • When replacing the skid control ECU (brake actuator assembly), perform zero point calibration.

  • When the entry start function does not operate, check the entry and start system (for start function)*.

  • *: w/ Entry and Start System

PROCEDURE

  1. READ VALUE USING GTS (BRAKE CANSEL SWITCH)

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Radar Cruise1 / Data List.

    5. Read the Data List according to the display on the GTS.

      OK

      Display changes according to brake pedaloperation described in above table.

      1. for 2AD-FHV, 2AD-FTV:

        Powertrain > Radar Cruise1 > Data List

        Tester Display

        Measurement Item

        Range

        Normal Condition

        Inspection Item

        Stop Light Switch 1

        Stop light switch status

        ON or OFF

        ON: Brake pedal depressed

        OFF: Brake pedal released

        -

        Powertrain > Radar Cruise1 > Data List

        Tester Display

        Stop Light Switch 1

      2. for 2AR-FE, 3ZR-FE, 3ZR-FAE:

        Powertrain > Radar Cruise1 > Data List

        Tester Display

        Measurement Item

        Range

        Normal Condition

        Inspection Item

        Brake Cancel Switch

        Stop light switch status

        ON or OFF

        ON: Brake pedal depressed

        OFF: Brake pedal released

        -

        Powertrain > Radar Cruise1 > Data List

        Tester Display

        Brake Cancel Switch

      3. for 2WW:

        Powertrain > Cruise Control > Data List

        Tester Display

        Measurement Item

        Range

        Normal Condition

        Inspection Item

        Brake Cancel Switch

        Stop light switch status

        ON or OFF

        ON: Brake pedal depressed

        OFF: Brake pedal released

        -

        Powertrain > Cruise Control > Data List

        Tester Display

        Brake Cancel Switch

    Result

    Proceed to

    OK

    NG
    NG

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

    OK

  2. 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

    Result

    Proceed to

    OK (w/ Entry and Start System)

    A

    OK (w/o Entry and Start System)

    B

    NG

    C
    B

    CHECK HARNESS AND CONNECTOR (STP2 TERMINAL VOLTAGE)Click here

    C

    GO TO LIGHTING SYSTEM

    Click here

    A

  3. CHECK HARNESS AND CONNECTOR (STPO TERMINAL VOLTAGE)

    1. Turn the ignition switch off.

    2. E296982C19

      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A80-26 (STPO) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))Click here

    OK

  4. PERFORM ACTIVE TEST USING GTS (STOP LIGHT RELAY)

    1. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.

    2. Perform "Active Test" according to the display on GTS.

      Chassis > ABS/VSC/TRC > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      Stop Light Relay

      Stop lights

      ON or OFF

      Test possible at vehicle speed of 0 km/h (0 mph)

      Chassis > ABS/VSC/TRC > Active Test

      Tester Display

      Stop Light Relay

    3. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

    4. Check the stop light switch assembly operation using the Data List and stop light operation by performing an Active Test.

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Stop Light Relay Output

      Stop light control relay output

      ON or OFF

      ON: Relay output on (Stop light on)

      OFF: Relay output off (Stop light off)

      -

      Chassis > ABS/VSC/TRC > Data List

      Tester Display

      Stop Light Relay

    Result

    Result

    Proceed to

    When Active Test performed, Data List item not changes between ON and OFF

    A

    When Active Test performed, Data List item changes between ON and OFF and stop lights turn on and off

    B
    B

    CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))Click here

    A

  5. INSPECT SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

    1. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.

    2. Perform "Active Test" according to the display on GTS.

      Chassis > ABS/VSC/TRC > Active Test

      Tester Display

      Measurement Item

      Control Range

      Diagnostic Note

      Stop Light Relay

      Stop lights

      ON or OFF

      Test possible at vehicle speed of 0 km/h (0 mph)

      Chassis > ABS/VSC/TRC > Active Test

      Tester Display

      Stop Light Relay
    3. E337400C01

      *a

      Component with harness connected

      (Stop Light Switch Assembly)

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A77-4 (ACC) - Body ground

      Active test is OFF

      11 to 14 V

      A77-4 (ACC) - Body ground

      Active test is ON

      Below 1.5 V

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE STOP LIGHT SWITCH ASSEMBLY

    Click here

    NG

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

    Click here

  6. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))

    1. Disconnect the A80 skid control ECU (brake actuator assembly) connector.

    2. Disconnect the A77 stop light switch assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A80-35 (STP) - A77-1 (OUT)

      Always

      Below 1 Ω

      A80-35 (STP) or A77-1 (OUT) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY))

    1. Disconnect the A80 skid control ECU (brake actuator assembly) connector.

    2. Disconnect the A77 stop light switch assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A80-26 (STPO) - A77-4 (ACC)

      Always

      Below 1 Ω

      A80-26 (STPO) or A77-4 (ACC) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE STOP LIGHT SWITCH ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  8. CHECK HARNESS AND CONNECTOR (STP2 TERMINAL VOLTAGE)

    1. Turn the ignition switch off.

    2. E296982C20

      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      A80-5 (STP2) - Body ground

      Stop light switch assembly on (Brake pedal depressed)

      8.5 to 14 V

      A80-5 (STP2) - Body ground

      Stop light switch assembly off (Brake pedal released)

      Below 1.5 V

    Result

    Proceed to

    OK

    NG
    OK

    CHECK HARNESS AND CONNECTOR (STPO TERMINAL VOLTAGE)Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH ASSEMBLY - BATTERY)

    1. Disconnect the stop light switch assembly connector.

    2. E270087C07

      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A77-7 (B) - Body ground

      Always

      11 to 14 V

      A77-6 (B) - Body ground

      Ignition switch ON

      11 to 14 V

      A77-6 (B) - Body ground

      Ignition switch off

      Below 1 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Disconnect the ECM connector.

    2. E217720C22

      *a

      Front view of wire harness connector

      (to ECM)

      for 2AR-FE:

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A62-24 (ST1-) - Body ground

      Ignition switch ON, brake pedal depressed

      Below 1.5 V

      Ignition switch ON, brake pedal released

      7.5 to 14 V

      A62-11 (STP) - Body ground

      Brake pedal depressed

      7.5 to 14 V

      Brake pedal released

      Below 1.5 V
    3. E217720C23

      *a

      Front view of wire harness connector

      (to ECM)

      for 3ZR-FAE, 3ZR-FE:

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A62-10 (ST1-) - Body ground

      Ignition switch ON, brake pedal depressed

      Below 1.5 V

      Ignition switch ON, brake pedal released

      7.5 to 14 V

      A62-9 (STP) - Body ground

      Brake pedal depressed

      7.5 to 14 V

      Brake pedal released

      Below 1.5 V
    4. E207340C03

      *a

      Front view of wire harness connector

      (to ECM)

      for 2AD-FHV, 2AD-FTV:

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A61-34 (ST1-) - Body ground

      Ignition switch ON, brake pedal depressed

      Below 1.5 V

      Ignition switch ON, brake pedal released

      7.5 to 14 V

      A61-35 (STP) - Body ground

      Brake pedal depressed

      7.5 to 14 V

      Brake pedal released

      Below 1.5 V
    5. E217720C24

      *a

      Front view of wire harness connector

      (to ECM)

      for 2WW:

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      A62-10 (ST1-) - Body ground

      Ignition switch ON, brake pedal depressed

      Below 1.5 V

      Ignition switch ON, brake pedal released

      7.5 to 14 V

      A62-48 (STP) - Body ground

      Brake pedal depressed

      7.5 to 14 V

      Brake pedal released

      Below 1.5 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK STOP LIGHT SWITCH ASSEMBLY

    1. Temporarily replace the stop light switch assembly with a new or normally functioning one.

      Click here

    2. Clear the DTCs.

      Click here

      1. for 2AD-FHV, 2AD-FTV:

        Powertrain > Radar Cruise1 > Clear DTCs

      2. for 2AR-FE, 3ZR-FE, 3ZR-FAE:

        Powertrain > Radar Cruise1 > Clear DTCs

      3. for 2WW:

        Powertrain > Cruise Control > Clear DTCs

    3. Check for DTCs.

      Click here

      1. for 2AD-FHV, 2AD-FTV:

        Powertrain > Radar Cruise1 > Trouble Codes

      2. for 2AR-FE, 3ZR-FE, 3ZR-FAE:

        Powertrain > Radar Cruise1 > Trouble Codes

      3. for 2WW:

        Powertrain > Cruise Control > Trouble Codes

    Result

    Result

    Proceed to

    DTC is not output

    A

    DTC P0571 is output

    B
    A

    END (STOP LIGHT SWITCH ASSEMBLY WAS DEFECTIVE)

    B

    REPLACE ECM

    for 2AD-FHV:Click here

    for 2AD-FTV:Click here

    for 2AR-FE:Click here

    for 3ZR-FAE:Click here

    for 3ZR-FE:Click here

    for 2WW:Click here