Throttle Position Sensor (TPS)

The Throttle Position Sensor is a potentiometer (variable resistor) which attaches to the throttle shaft and sends a voltage signal to the computer, telling it how far open the throttle is. The resistance across it is about 5,000 ohms. At idle the voltage is about 0.7 V and wide open throttle is about 4.0 V. You can measure the voltage with ignition on and engine off, using a voltmeter.