Throttle Position Sensor: Description and Operation

COMPONENT DESCRIPTION AND OPERATION


In Relation to Transmission Control Module (TCM)






Throttle Position Sensor
The throttle position sensor detects the throttle valve position and sends a signal to the TCM.

Throttle Position Switch
Consists of a wide open throttle position switch and a closed throttle position switch.

The wide open throttle position switch sends a signal to the TCM when the throttle valve is open at least 1/2 of the full throttle position. The closed throttle position switch sends a signal to the TCM when the throttle valve is fully closed.




In Relation to Engine Control Module (ECM)






Throttle Position Sensor
The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.

Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This one controls engine operation such as fuel cut.

On the other hand, the "Wide open and closed throttle position switch", which is built into the throttle position sensor unit, is not used for engine control.