Throttle Position Sensor
WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2002 Mercury Grand Marquis, 2002 Lincoln Town Car, 2002 Ford Crown Victoria, 2001 Mercury Mountaineer, and 2001 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.
The Throttle Position (TP) sensor is a potentiometer mounted on the throttle body. The PCM receives a signal from the TP sensor relaying throttle plate position. PCM uses TP sensor signal to help determine EPC pressure, shift scheduling and TCC operation. TP sensor failure will cause PCM to operate in fail safe mode and raise line pressure to prevent transmission damage. This condition will result in harsh engagements, firm shift feel, abnormal shift schedule, and TCC not engaging or cycling.