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 assembly sends a signal to the ECM. When the ECM receives this signal, it cancels the cruise control.

Fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit.

The cancel condition occurs when battery voltage is applied to terminal STP.

When the brake is applied, battery 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.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT STOP LIGHT SWITCH

(a) Disconnect the stop light switch connector.

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





Standard resistance:





(c) Connect the stop light switch connector.

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

2. 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) Connect the stop light switch connector.

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

3. CHECK ECM

(a) Disconnect the ECM connector.

(b) Turn the ignition switch on (IG).

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





Standard voltage:





(d) Connect the ECM connector.

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

OK -- REPLACE ECM