Throttle position sensor

The accelerator pedal sensors are used in electronic throttle control or "drive by wire" systems, and the most common use of a wide open throttle sensor is for the kick-down function on automatic transmissions.

Non contact type TPS work on the principle of Hall effect or inductive sensors, or magnetoresistive technologies, wherein generally the magnet or inductive loop is the dynamic part which is mounted on the butterfly valve throttle spindle/shaft gear and the sensor & signal processing circuit board is mounted within the ETC gear box cover and is stationary.

When the magnet/inductive loop mounted on the spindle which is rotated from the lower mechanical stop to WOT, there is a change in the magnetic field for the sensor.

The change in the magnetic field is sensed by the sensor and the voltage generated is given as the input to the ECU.

Normally a two pole rare-earth magnet is used for the TPS due to their high Curie temperatures required in the under-hood vehicle environment.