Throttle Position Sensor
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2003 Mazda B4000, 2003 Mazda B3000, 2003 Mazda B2300, 2002 Mazda B4000, and 2002 Mazda B3000. However, it is still accessible from the selected car via links, so may be relevant.
The Throttle Position (TP) sensor is a potentiometer mounted to the engine throttle body. PCM receives a signal from the TP sensor relaying throttle plate position. TP sensor is used for shift scheduling, EPC and TCC control. TP sensor failure will cause PCM to operate in fail safe mode, and PCM will 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.