Circuit Description

Throttle Position (TP) sensor is a potentiometer whose resistance value changes along with throttle valve position. The PCM provides a 5 volt reference voltage to TP sensor. PCM reads voltage across TP sensor and uses voltage to calculate percentage of throttle valve opening. TP sensor resistance decreases as throttle valve opening increases. When TP sensor resistance decreases, voltage being monitored by PCM increases. TP sensor resistance increases when throttle valve opening decreases, therefore voltage being monitored by PCM will decrease.

• TP sensor input to PCM is less than 0.1 volt and throttle valve is in closed position.
• TP sensor input to PCM is greater than 4.9 volts and throttle valve is at WOT position.

When DTC sets, MIL will illuminate. PCM will record operating conditions at time of failure and store information in freeze frame buffer. TP sensor angle will default to zero percent.