Throttle Position Sensor: Description and Operation

The TPS is connected to the throttle valve shaft in the throttle body unit. The TPS is a potentiometer with one connection to ground and a second to a current regulated 5 volt reference source in the ECM. A third connection goes to the ECM and is used to measure the voltage from the TPS. As the throttle angle changes, so does the TPS voltage output. By monitoring TPS voltage output, the ECM can determine throttle valve angle and use this information, compared with information from other sensors, to calculate fuel delivery rate.