Aurora V8-4.0L VIN C (1996)
Throttle Position Sensor: Description and Operation
IAC Valve And TP Sensor
DESCRIPTION
The TP sensor is a potentiometer that is mounted on the throttle body and provides the PCM with information on throttle valve angle.
OPERATION
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 (close to 0°) the TP sensor output signal is low (below 1 volt) and at WOT (greater than 80°) the TP sensor output signal is
high (above 4 volts). Because the TP sensor is not adjustable, the PCM must account for build tolerances that could affect the TP sensor output at
closed throttle. The PCM uses a learning process so that it can correct for variations of up to 6° of throttle angle. 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 DTC.
