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 sends a signal to the ECM. When the ECM receives this signal, it cancels the 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 SW fuse and the stop light switch, and the ECM turns the cruise control off.

DTC No. DTC Detection Condition Trouble Area
P0571 Voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for 0.5 sec. or more

  • Stop light switch

  • Stop light switch circuit

  • ECM

WIRING DIAGRAM

A015ZXGE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. A015ZQ9E03

      Disconnect the stop light switch connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A22-2 - Body ground Always 11 to 14 V
      A22-4 - Body ground Engine switch on (IG) 11 to 14 V

    3. Reconnect the stop light switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT STOP LIGHT SWITCH


    1. A0163A4E01

      Remove the stop light switch Click here.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      1 - 2 Switch pin not pushed Below 1 Ω
      3 - 4 Switch pin not pushed 10 kΩ or higher
      1 - 2 Switch pin pushed 10 kΩ or higher
      3 - 4 Switch pin pushed Below 1 Ω

    3. Reinstall the stop light switch Click here.


    NG

    REPLACE STOP LIGHT SWITCH Click here

    OK

  3. CHECK ECM


    1. A0160F0E01

      Disconnect the ECM 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 Condition Specified Condition
      A5-13 (STP) - Body ground Brake pedal depressed 11 to 14 V
      A5-13 (STP) - Body ground Brake pedal released Below 1 V
      A5-12 (ST1-) - Body ground Brake pedal depressed Below 1 V
      A5-12 (ST1-) - Body ground Brake pedal released 11 to 14 V

    4. Reconnect the ECM connector.


    NG

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

    OK

    REPLACE ECM (for 2UR-GSE) Click here