Circuit Description

Throttle Position (TP) sensor is a potentiometer whose resistance value changes along with throttle valve position. The ECM provides a 5 volt reference voltage to TP sensor. ECM 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 ECM increases. TP sensor resistance increases when throttle valve opening decreases, therefore voltage being monitored by ECM will decrease.

DTC will set when signal being received conflicts with MAF reading, battery voltage is greater than 7 volts and TP sensors No. 1 and No. 2 reading differs by greater than 6.3 percent for more than 180 milliseconds. When DTC sets, MIL will illuminate. ECM will record operating conditions at time of failure and store information in freeze frame buffer.