Throttle Position Sensor: Description and Operation

Checking Throttle Sensor:

PURPOSE
Sensor informs PCME of throttle valve position. Idle switch signals PCME when throttle valve is completely closed.

LOCATION
Side of throttle body.

OPERATION
Sensor is a potentiometer attached to the throttle body and splined to the throttle shaft. It rotates with the shaft as the throttle opens and closes. Varying potentiometer resistance alters the reference voltage supplied by the PCME, allowing it to read throttle valve opening angle. This input is used in PCME calculations for outputs such as fuel injection quantity, pressure regulator solenoid valve control and idle speed control. Integral with the position sensor is an idle switch. It is an ON/OFF switch detecting when the throttle valve is closed.