Throttle Position Sensor: Description and Operation

The throttle position sensor is connected to the throttle valve shaft on the throttle body, and detects the throttle valve opening.

The throttle opening is detected by the potentiometer as follows. A 5-volt reference voltage is applied to the sensor from ECM (PCM) and as its brush moves over the print resistance according to the throttle valve opening, the output voltage varies accordingly. By monitoring sensor output voltage, ECM (PCM) detects the throttle valve opening.

ECM (PCM) uses the signal from TP sensor as one of the signals to control various devices.