Throttle Position Sensor

The TPS is mounted on the side of the throttle body, opposite the throttle lever. A 5-volt reference voltage is supplied to the TPS and a signal circuit transmits the dropped voltage to the ECM. With key on, engine off, TPS voltage signal should be 1.25 volts (throttle closed) or less. An ALDL Scan tester may be used to check TPS voltage. If voltage is greater than 1.25 volts, replace the TPS.