Throttle Position Sensor: Description and Operation

Throttle Position Sensor:

PURPOSE
Informs the ECM of throttle valve angle.

LOCATION
On the throttle chamber.

TPS Output Voltage Characteristics:

OPERATION AND CONSTRUCTION
The throttle position sensor consisting of a contact point (idle switch) and a potentiometer is connected to the throttle valve shaft on the throttle body, and detects the throttle valve opening.

The throttle opening in the idle state is detected by means of the contact point which turns ON in that state.

But beyond that the full opening is detected by the potentiometer as follows.

A 5-volt reference voltage is applied to the sensor from ECM and as its brush moves over the print resistance according to the throttle valve opening, the output voltage varies accordingly.

By monitoring the sensor output voltage, ECM detects the throttle valve opening and its change.