Stop Light Switch Circuit - Cruise Control System

CRUISE CONTROL: CRUISE CONTROL SYSTEM: P0571/52: Stop Light Switch Circuit

DTC P0571/52 - Stop Light Switch 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.
When the brake pedal is depressed, battery voltage is applied to terminal STP of the ECM through the stop fuse and stop light switch assembly, causing the ECM to cancel cruise control operation.





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: When troubleshooting in accordance with Problem Symptoms Table, be sure to follow the table before replacing the ECM.

PROCEDURE

1. INSPECT STOP LIGHT SWITCH ASSEMBLY




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





(c) Reconnect the stop light switch connector.
NG -- REPLACE STOP LIGHT SWITCH ASSEMBLY
OK -- Continue to next step.
2. CHECK WIRE HARNESS (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.
3. CHECK WIRE HARNESS (ECM - STOP LIGHT SWITCH)




(a) Disconnect the ECM connectors.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





(d) Reconnect the ECM connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM