Throttle Position Sensor: Description and Operation

Throttle Position Sensor (TPS):

The Throttle Position Sensor (TPS) is a variable resistor, mounted on the end of the throttle shaft, whose output voltage is dependent on the angle of the throttle blade (or throttle opening).

The engine controller applies a 5 volt reference signal to the TPS, and determines the current angle of the throttle blade from TPS output voltage. TPS output voltage ranges from approximately 1 Volt, at idle position, to approximately 4 Volts, at Wide Open Throttle (WOT).

The engine controller uses TPS voltage and other inputs to determine the proper air/fuel mixture and ignition timing for current operating conditions.