Throttle Position Sensor
WARNING: This page is about a different car, the 2002 Mazda 626 and 2001 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.
Throttle Position (TP) sensor is a potentiometer mounted to the engine throttle body. The PCM receives a signal from the TP sensor relaying throttle plate position. TP sensor failure will cause PCM to operate in fail safe mode and raise line pressure to prevent transaxle damage. This condition will result in harsh engagements, firm shift feel, abnormal shift schedule and TCC not engaging or cycling.