Throttle Position Sensor: Description and Operation

PURPOSE
The Throttle Position Sensor, mounted on the throttle body, is a potentiometer that converts throttle plate angle and opening speed into a voltage signal (input) for the Powertrain Control Module (PCM).

CONSTRUCTION
The Throttle Position Sensor contains a pivot arm that moves along a curved resistor. One of the sensor leads supplies a 5 Volt reference signal (sent by the PCM) to the resistor. The second lead is used to ground the resistor. The third lead is for the voltage signal to the PCM.

OPERATION
As the throttle plates move, the pivot arm moves along the curved resistor and receives a varying voltage signal. The PCM reads this signal and converts it into throttle plate angle. The voltage signal ranges from approximately 0.5 Volts at idle to approximately 5.0 Volts at wide open throttle.
The Throttle Position Sensor will also set a Diagnostic Trouble Code (DTC) if the PCM determines the output signal is out of the normal operating range.