Throttle Position Sensor: Description and Operation

PURPOSE/OPERATION
The throttle position sensor converts the degree of opening of the throttle valve to voltage and inputs that voltage (as signals) to the engine control module. The engine control module, based upon those signals, then regulates the amount of fuel injection.
5 Volts is supplied to the throttle position sensor by engine control module after which it passes through the resistance within the sensor and is grounded at the engine control module.
When the throttle valve shaft is rotated all the way from the idle position to the fully open position, the resistance between the throttle position sensor's variable-resistance terminal and the ground terminal also increases in accordance with that rotation, and, as a result, the voltage of the throttle position sensor 's variable-resistance terminal also becomes higher in accordance with that rotation.