Throttle Position Sensor: Description and Operation

Throttle Position Sensor:

THROTTLE POSITION SENSOR (TPS)-PCM INPUT
The TPS is mounted on the throttle body and connected to the throttle blade shaft. The TPS is a variable resistor that provides the (PCM) with an input signal (voltage) representing throttle blade position. As the position of the throttle blade changes, the resistance of the TPS changes.

The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The TPS output voltage to the PCM varies from approximately 0.5 volt at minimum throttle opening (idle) to 4 volts at wide open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions and adjust fuel injector pulse width and ignition timing.