P0571

CRUISE CONTROL: CRUISE CONTROL SYSTEM: P0571: Brake Switch "A" Circuit
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 fuse and the stop light switch, and the ECM turns the cruise control off.





WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

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

(a) Disconnect the stop light switch connector.





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

Standard Voltage:





(c) Reconnect the stop light switch connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. INSPECT STOP LIGHT SWITCH

(a) Remove the stop light switch Components.





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

Standard Resistance:





(c) Install the stop light switch Installation.

NG -- REPLACE STOP LIGHT SWITCH Components
OK -- Continue to next step.

3. CHECK ECM

(a) Disconnect the ECM connector.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





Result:





(d) Reconnect the ECM connector.

C -- REPLACE ECM (for 2AZ-FE) Components

B -- REPLACE ECM (for 2ZR-FE) Components

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