Throttle Position Sensor: Description and Operation
PURPOSEPCM uses sensor input with other inputs to determine current operating conditions.
PCM adjusts air/fuel mixture (injector pulse width) and ignition timing.
OPERATION
PCM supplies 5 volt sensor reference voltage.
Sensor is a variable resistor (potentiometer), whose resistance is dependent on the angle of the throttle blade (or throttle opening).
Output voltage ranges from approximately 1 Volt, (at idle position), to approximately 4 Volts, (at Wide Open Throttle).