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Home >> Cadillac >> 1998 >> Seville SLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0121 - TP Sensor Circuit Insufficient Activity >> Circuit Description
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Circuit Description

TP sensor is a potentiometer. At low throttle angle, TP sensor voltage is low. PCM uses TP sensor signal voltage to determine idle, Wide Open Throttle (WOT), deceleration enleanment and acceleration enrichment. This test determines when the TP sensor reading is too high and out of its estimated range for the current engine speed. PCM monitors changes in TP sensor. If change is .6 degree or less within .1 second, PCM compares the current throttle position with a stored value. If current throttle position is greater than the stored value, TP sensor is considered stuck and DTC will set.

Conditions for setting DTC: