Throttle Position Sensor (TPS)

The TPS is mounted on the side of throttle body, opposite the throttle lever. A 5-volt reference voltage is supplied to TPS, and a signal circuit transmits the dropped voltage to ECM. With ignition on and 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 TPS.