Throttle Position Sensor: Description and Operation

PURPOSE
The Throttle Position (TP) sensor monitors throttle angle. The Powertrain Control Module (PCM) determines four operating modes from the throttle angle signal:
- Closed throttle (idle or deceleration)
- Part throttle (cruise or moderate acceleration)
- Wide open throttle (maximum acceleration, de-choke on crank)
- Throttle angle rate

The PCM uses the sensor input and reacts to control spark advance, Exhaust Gas Recirculation (EGR) flow, air/fuel ratio and A/C clutch cutout.

OPERATION
The TP sensor responds to the accelerator pedal movement. The TP sensor is a potentiometer that transforms the throttle plate opening angle into output voltage, and sends the voltage signal to the PCM.

CONSTRUCTION
The TP sensor is rotary potentiometer that has a pivot arm that moves along a curved resistor. The sensor housing has a three blade gold plated electrical connector.