Dynamic Laser Cruise Control System

CRUISE CONTROL: DYNAMIC LASER 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 FOR DTC (IN VEHICLE STABILITY CONTROL SYSTEM)

(a) Check for DTCs in Vehicle Stability Control System Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC is not output.

NG -- GO TO DTC CHART Vehicle Stability Control System
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Laser Cruise / Data List.

(e) Check the Data List for proper functioning of the stop light switch.

ECM (Laser Cruise)





OK:

Normal conditions listed above are displayed.

Result





D -- REPLACE ECM Removal

C -- REPLACE ECM Removal

B -- REPLACE ECM Removal
A -- Continue to next step.

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

(a) Disconnect the A4 connector from the stop light switch.





(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.

4. INSPECT STOP LIGHT SWITCH

(a) Remove the stop light switch Removal.





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

Standard Resistance:





(c) Reinstall the stop light switch.

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

5. CHECK ECM

(a) Disconnect the A27 connector from the ECM.





(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.

D -- REPLACE ECM Removal

C -- REPLACE ECM Removal

B -- REPLACE ECM Removal

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