Circuit Description

Throttle Position (TP) sensor is mounted on throttle body and detects throttle opening angle. When throttle valve is closed, approximately 0.3-0.8 volt is applied to TP input circuit. Voltage will increase in proportion to amount of throttle valve opening angle. At Wide Open Throttle (WOT), TP input circuit voltage is approximately 3.2-4.9 volts. PCM judges vehicle driving condition from TP sensor input and determines air-fuel correction, power increase correction and fuel-cut control. DTC P0121 will set when vehicle speed drops from 20 MPH (30 KM/H) or more to 0 MPH (0 KM/H), and TP sensor value is out of range.