Dtc P0571 Brake Switch A Circuit

Engine Hybrid System. Corolla. Zre142 Aze141
Cruise Control. Corolla. Zre142 Aze141

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

INSPECT STOP LIGHT SWITCH ASSEMBLY

CHECK ECM

DTC 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 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 cruise control off.

DTC No.
DTC Detection Condition
Trouble Area
P0571
When voltage of STP terminal and that of ST1- terminal of ECM are less than 1 V for 0.5 sec. or more
  1. Stop light switch assembly
  2. Stop light switch circuit
  3. ECM

WIRING DIAGRAM


Corolla. Zre142 Aze141.Cruise Control.Cruise Control System. Dtc P0571 Brake Switch A Circuit


Corolla. Zre142 Aze141.Cruise Control.Cruise Control System. Dtc P0571 Brake Switch A Circuit


INSPECTION PROCEDURE

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


    Corolla. Zre142 Aze141.Cruise Control.Cruise Control System. Dtc P0571 Brake Switch A Circuit

  1. Disconnect the stop light switch assembly connector.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A1-2 - Body ground
    		Always
    		11 to 14 V
    A1-3 - Body ground
    		Ignition switch ON
    		11 to 14 V

  1. Reconnect the stop light switch assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.INSPECT STOP LIGHT SWITCH ASSEMBLY


    Corolla. Zre142 Aze141.Cruise Control.Cruise Control System. Dtc P0571 Brake Switch A Circuit

  1. Remove the stop light switch assembly (COROLLA_ZRE142 RM0000033ZK00DX.html).

  1. 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

  1. Install the stop light switch assembly (COROLLA_ZRE142 RM000002VPN018X.html).



NG
REPLACE STOP LIGHT SWITCH ASSEMBLY (COROLLA_ZRE142 RM0000033ZK00DX.html)
OK


3.CHECK ECM


    Corolla. Zre142 Aze141.Cruise Control.Cruise Control System. Dtc P0571 Brake Switch A Circuit

  1. Disconnect the ECM connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A50-36 (STP) - Body ground
    		Brake pedal depressed
    		11 to 14 V
    A50-36 (STP) - Body ground
    		Brake pedal released
    		Below 1 V
    A50-35 (ST1-) - Body ground
    		Brake pedal depressed
    		Below 1 V
    A50-35 (ST1-) - Body ground
    		Brake pedal released
    		11 to 14 V
    Result:
    Result
    		Proceed to
    NG
    		A
    OK (for 2ZR-FE)
    		B
    OK (for 2AZ-FE)
    		C

  1. Reconnect the ECM connector.



B
REPLACE ECM (COROLLA_ZRE142 RM0000030LQ012X.html)

C
REPLACE ECM (COROLLA_ZRE142 RM000002WT402ZX.html)
A

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