Throttle Position Sensor
WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2002 Saturn Vue, 2002 Pontiac Montana, 2002 Pontiac Aztek, 2002 Oldsmobile Silhouette, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.
The TP sensor is a variable mechanical resistor connected directly to throttle shaft linkage. TP sensor has 3 wires connected to it. One is connected to a 5-volt reference voltage supply from PCM, another is connected to PCM ground and third is a signal return which is monitored by PCM. Voltage signal from TP sensor varies from closed throttle (0.5-1.0 volt) to wide open throttle (4.5-5 volts). PCM uses this signal to determine control of fuel, idle speed, spark timing and Torque Converter Clutch (TCC). A problem in TP sensor circuit may set a related DTC.