DeVille V8-4.9L VIN B (1995)
Throttle Position Sensor: Description and Operation
TP Sensor
DESCRIPTION
The Throttle Position (TP) Sensor is a potentiometer that is mounted on the throttle body and provides the Powertrain Control Module (PCM)
with information on throttle valve angle. The PCM provides a 5 volt reference signal and a ground to the TP sensor and the sensor returns a signal
voltage that changes with throttle valve angle. At closed throttle (approximately zero degrees) the TP sensor output signal is low (below 1 volt)
and at WOT (approximately 85 degrees) the TP sensor output signal is high (close to 5 volts).
The PCM uses TP information to modify fuel control based on throttle valve angle. For example, power enrichment occurs when the throttle angle
approaches WOT. Acceleration enrichment occurs when the throttle angle increases rapidly (similar to an accelerator pump on a carburetor). A
faulty TP sensor may cause various driveability conditions and should set a Diagnostic Trouble Code.
