Throttle Position Sensor
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The Throttle Position (TP) sensor is a variable mechanical resistor connected directly to the throttle shaft linkage. The TP sensor has 3 wires connected to it. One is connected to a 5-volt reference voltage supply from PCM, the second is connected to PCM ground and the third is the signal return which is monitored by PCM. The voltage signal from the TP sensor varies from closed throttle (.5-1.0 volt) to Wide Open Throttle (WOT) (4.5-5.0 volts). This signal is used by PCM for determining control of fuel, idle speed, spark timing and converter clutch. Failure in TP sensor circuit should set a related DTC.