DTC P0121, DTC P0122 Or DTC P0123: TP Sensor: Description
WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.
The Throttle Position (TP) sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM. See Fig 1 .
Idle position of the throttle valve is determined by the ECM receiving the signal from the TP sensor. This sensor controls engine operation such as fuel cut. On the other hand, the wide open and closed TP switch, which is built into the TP sensor unit, is not used for engine control.