Stop Light Switch Circuit

STOP LIGHT CIRCUIT DESCRIPTION
The purpose of this circuit is to prevent the engine from stalling when the brakes are suddenly applied while driving in lock-up condition.
When the brake pedal is operated, this switch sends a signal to the engine control module (ECM). Then the ECM cancels operation of the lock-up clutch while braking is in progress.

WIRING DIAGRAM





INSPECTION PROCEDURE
1. Check operation of stop lights.
OK - Go to Step 2.
NG - Repair stop light circuit.
2. Check stop light signal.




a. Connect a voltmeter to terminals TT (+) and E1 (-) of the data link connector (DLC1).
b. Turn ignition switch ON. (DO NOT START ENGINE).
c. Fully depress the accelerator pedal until the voltmeter indicates 8 volts and hold it.
d. Depress and release the brake pedal and check the voltage.
Expected Results:
Pedal depressed - 0 volts
Pedal released - 8 volts
OK - Proceed to next circuit inspection shown on matrix chart.
NG - Go to Step 3.
3. Check harness and connectors between stop light switch and ECM.
OK - Check and replace engine control module (ECM).
NG - Repair or replace harness or connector as indicated.