B2300 Regular Cab 2WD L4-2.3L VIN A (1997)
Brake Signal: Description and Operation
BRAKE ON/OFF (BOO) SWITCH
Sends a battery voltage signal to PCM when depressing brake pedal.
Operation
PCM adjusts or controls the following:
1. Maintains idle speed with brake applied
2. A/C compressor ON/OFF
3. Disengages torque converter clutch
NOTE: If all stop lamp bulbs are open, a high voltage is present at PCM due to a pull-up resistor in PCM. This provides fail safe function in event
circuit to BOO switch has failed.
