Throttle Position Sensor: Description and Operation

Throttle Position Sensor:

PURPOSE
The Throttle Position Sensor (TPS) sensor is a variable resistor (potentiometer) that is mounted on the throttle body unit and driven by the throttle shaft. It's signal is used by the Engine Control Module (ECM) to detect throttle movement and position.

OPERATION
A 5 volt reference signal is applied from the ECM and a ground signal. When the throttle is opened the sensor resistance changes which is read as a varying voltage signal. At idle position the sensor voltage is approximately. 0.5V and approximately. 4.5 V at full throttle.