P0571

CRUISE CONTROL: CRUISE CONTROL SYSTEM: P0571: Brake Switch "A" Circuit

DTC 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.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK STOP LIGHT SWITCH OPERATION
(a) Check that the stop light lights up when brake pedal is depress and turns OFF when the brake pedal is released.

NG -- INSPECT STOP LIGHT SWITCH CIRCUIT
OK -- Continue to next step.

2. INSPECT STOP LIGHT SWITCH

(a) Remove stop light switch Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(a) Reconnect the stop light switch connector.
(b) Remove the ECM with connectors still connected.
(c) Turn the ignition switch to ON.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:

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