CRUISE CONTROL SYSTEM, Diagnostic DTC:P0571

DTC Code DTC Name
P0571 Stop Light Switch Circuit Malfunction

DESCRIPTION

When the brake pedal is depressed, the stop light switch sends a signal to the ECM. Upon receiving the signal, the ECM cancels cruise control. Even if there is a malfunction in the stop light signal circuit while cruise control is in operation, normal driving is maintained due to a fail-safe function.

When the brake pedal is depressed, positive voltage is applied to terminal STP of the ECM through the STOP fuse and stop light switch, and the ECM cancels cruise control.

DTC Code DTC Detection Condition Trouble Area
P0571 The voltages of terminals ST1- and STP of the ECM are both below 1 V for 0.5 seconds or more.

  • Stop light switch circuit

  • Stop light switch assembly

  • ECM

WIRING DIAGRAM

A003F96E03
A003F96E04

INSPECTION PROCEDURE

Note

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

PROCEDURE


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


    1. A003AUVE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Stop Light Switch Assembly)

      Disconnect the stop light switch assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B2-2 - Body ground Always 11 to 14 V
      B2-4 - Body ground Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT STOP LIGHT SWITCH ASSEMBLY


    1. Remove the stop light switch assembly.

    2. Inspect the stop light assembly Click here.


    NG

    REPLACE STOP LIGHT SWITCH ASSEMBLY

    OK

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


    1. Disconnect the B2 stop light switch assembly connector.

    2. Disconnect the B72*1 or B71*2 ECM connector.


      • *1: for 1KD-FTV

      • *2: for 2TR-FE

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

      Standard Resistance
      for 1KD-FTV
      Tester Connection Condition Specified Condition
      B2-3 - B72-34 (ST1-) Always Below 1 Ω
      B2-1 - B72-35 (STP)
      B2-3 - Body ground Always 10 kΩ or higher
      B2-1 - Body ground
      for 2TR-FE
      Tester Connection Condition Specified Condition
      B2-3 - B71-35 (ST1-) Always Below 1 Ω
      B2-1 - B71-36 (STP)
      B2-3 - Body ground Always 10 kΩ or higher
      B2-1 - Body ground
      Result
      Result Proceed to
      OK (for 1KD-FTV) A
      OK (for 2TR-FE) B
      NG C

    B

    REPLACE ECM Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE ECM Click here