Throttle Position Sensor: Description and Operation

Throttle Position Sensor (TPS) 4A-FE Engine:

Throttle Position Sensor (TPS) 4A-GE Engine:

The TPS is mounted on the throttle valve body and sends a varying voltage signal to the ECU based on throttle valve position. The ECU can then adjust fuel delivery based on acceleration, deceleration, full throttle (WOT) or idle. The TPS inputs the ECU through terminal PSW, (on 4A-FE), or terminal VTA, (on 4A-GE). Additionally on the 4A-GE model, terminal VCC supplies input voltage to the TPS from the ECU .