Circuit Description

Throttle Position (TP) sensor is a potentiometer whose resistance value changes along with throttle valve position. 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.

When DTC sets, MIL will illuminate after 2 consecutive ignition cycles in which diagnostic runs with active fault. PCM will record operating conditions at time of diagnostic failure and store information in freeze frame buffer.