Circuit Description

Throttle Position (TP) sensor measures amount of throttle valve opening. TP sensor signal voltage varies from about 0.25 volts at closed throttle to about 4 volts at wide open throttle.

TP signal is used by PCM for fuel control and most PCM controlled outputs. PCM monitors throttle position and compares actual throttle positions from the TP sensor to a predicted TP value calculated from engine speed. If PCM detects a continuous open, DTC P0123 will set.