DYNAMIC RADAR CRUISE CONTROL SYSTEM, Diagnostic DTC:P0571/76

DTC Code DTC Name
P0571/76 Brake Switch "A" Circuit

DESCRIPTION

The ECM receives the brake demand signal from the driving support ECU assembly and transmits it to the skid control ECU (master cylinder solenoid).

The skid control ECU (master cylinder solenoid) receives a signal from the ECM and operates the skid control ECU (master cylinder solenoid).

The skid control ECU (master cylinder solenoid) operates simultaneously the stop light control relay assembly and illuminates the stop rights.

DTC No. DTC Detection Condition Trouble Area
P0571/76 While the dynamic radar cruise control system is operating (vehicle-to-vehicle distance control mode), the ECM detects the stop light control relay signal from the skid control ECU (master cylinder solenoid) for approximately 0.2 seconds or more.

  • Lighting system

  • Stop light control relay assembly

  • Skid control ECU (master cylinder solenoid)

  • Harness or connector

WIRING DIAGRAM

B001AKWE04

CAUTION / NOTICE / HINT

Note


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

  • After replacing the master cylinder solenoid, perform zero point calibration and store the system information Click here.

  • When the start function does not operate, check the Entry and Start System (for start function) Click here.

PROCEDURE


  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

    NG

    GO TO LIGHTING SYSTEM Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (STPO TERMINAL VOLTAGE)


    1. Turn the engine switch off.

    2. B0018TZE01
      Text in Illustration
      *a Front view of wire harness connector (to Skid Control ECU [Master Cylinder Solenoid])

      Disconnect the skid control ECU (master cylinder solenoid) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-16 (STPO) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY ASSEMBLY - SKID CONTROL ECU [MASTER CYLINDER SOLENOID]) Click here

    OK

  3. PERFORM ACTIVE TEST USING 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 the GTS.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop light control relay assembly Relay ON/OFF Observe the stop light (the stop lights do not come on for 2 to 5 seconds)

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

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Relay Output Stop light control relay assembly Stop light control relay assembly/ON or OFF

      ON: Relay output on (Stop light on)

      OFF: Relay output off (Stop light off)

      		 -
      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 (STP2 TERMINAL VOLTAGE) Click here

    A

  4. INSPECT SKID CONTROL ECU (MASTER CYLINDER SOLENOID)


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

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

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop light control relay assembly Relay ON/OFF Observe the stop light (the stop lights do not come on for 2 to 5 seconds)
    3. B0019SIE01
      Text in Illustration
      *a

      Component with harness connected

      (Stop Light Control Relay Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A58-9 (ACC) - Body ground Active test is ON Below 1.5 V
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE SKID CONTROL ECU (MASTER CYLINDER SOLENOID) Click here

    C

    REPLACE SKID CONTROL ECU (MASTER CYLINDER SOLENOID) Click here

    A

  5. REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY


    1. Replace the stop light control relay assembly.

      for LHD: Click here

      for RHD: Click here


    NEXT

  6. CHECK FOR DTC


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

      Tech Tips

      If the detection conditions are not met, the system cannot detect the malfunction.


      • Using the GTS, perform the Active Test "Stop Light Relay" with the ignition switch to ON.

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

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop light control relay assembly Relay ON/OFF Observe the stop light (the stop lights do not come on for 2 to 5 seconds)
      EBS Relay

      Stop light control relay assembly

      (Emergency brake signal)

      		 Relay ON/OFF -

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

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Relay Output Stop light control relay assembly Stop light control relay assembly/ON or OFF

      ON: Relay output on (Stop light on)

      OFF: Relay output off (Stop light off)

      		 -
      EBS Relay Stop light control relay assembly (Emergency brake signal)/ON or OFF

      ON: Relay on

      OFF: Relay off

      		 -

    5. Clear the DTCs Click here.

    6. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC C1380 is output A
      DTC C1380 is not output B

    A

    GO TO DTC C1380 Click here

    B

    END (STOP LIGHT CONTROL RELAY ASSEMBLY WAS DEFECTIVE)

  7. CHECK HARNESS AND CONNECTOR (STP2 TERMINAL VOLTAGE)


    1. Turn the engine switch off.

    2. B0018MEE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU [Master Cylinder Solenoid])

      Disconnect the skid control ECU (master cylinder solenoid ) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A24-45 (STP2) - Body ground Brake pedal depressed 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. REPLACE SKID CONTROL ECU (MASTER CYLINDER SOLENOID)


    1. Replace the skid control ECU (master cylinder solenoid).

      for LHD: Click here

      for RHD: Click here


    NEXT

  9. CHECK FOR DTC


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

      Tech Tips

      If the detection conditions are not met, the system cannot detect the malfunction.


      • Using the GTS, perform the Active Test "Stop Light Relay" with the ignition switch to ON.

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

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop lights ON / OFF Test possible at vehicle speed of 0 km/h (0 mph)
      EBS Relay

      Stop light control relay

      (Emergency brake signal)

      		 ON / OFF -

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

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Relay Output STOP terminal output condition/ON or OFF

      ON: Output

      ON: Not output

      		 -
      EBS Relay Stop light control relay (Emergency brake signal)/ON or OFF

      ON: Relay on

      OFF: Relay off

      		 -

    5. Clear the DTCs Click here.

    6. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC C1380 is output A
      DTC C1380 is not output B

    A

    GO TO DTC C1380 Click here

    B

    END (STOP LIGHT CONTROL RELAY ASSEMBLY WAS DEFECTIVE)

  10. CHECK HARNESS AND CONNECTOR (STOP LIGHT CONTROL RELAY ASSEMBLY - SKID CONTROL ECU [MASTER CYLINDER SOLENOID])


    1. Disconnect the A58 stop light control relay assembly connector.

    2. Disconnect the A24 skid control ECU (master cylinder solenoid) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A58-9 (ACC) - A24-16 (STPO) Always Below 1 Ω
      A58-9 (ACC) or A24-16 (STPO) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. REPLACE STOP LIGHT CONTROL RELAY ASSEMBLY


    1. Replace the stop light control relay assembly.

      for LHD: Click here

      for RHD: Click here


    NEXT

  12. CHECK FOR DTC


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

      Tech Tips

      If the detection conditions are not met, the system cannot detect the malfunction.


      • Using the GTS, perform the Active Test "Stop Light Relay" with the ignition switch to ON.

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

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Stop Light Relay Stop lights ON / OFF Test possible at vehicle speed of 0 km/h (0 mph)
      EBS Relay

      Stop light control relay

      (Emergency brake signal)

      		 ON / OFF -

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

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

      ABS/VSC/TRC
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Stop Light Relay Output STOP terminal output condition/ON or OFF

      ON: Output

      ON: Not output

      		 -
      EBS Relay Stop light control relay (Emergency brake signal)/ON or OFF

      ON: Relay on

      OFF: Relay off

      		 -

    5. Clear the DTCs Click here.

    6. Check for DTCs Click here.

      Result
      Result Proceed to
      DTC C1380 is output A
      DTC C1380 is not output B

    A

    GO TO DTC C1380 Click here

    B

    END (STOP LIGHT CONTROL RELAY ASSEMBLY WAS DEFECTIVE)