Throttle Position Sensor: Description and Operation

Typical Throttle Position Sensors:

PURPOSE
The Throttle Position (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.

OPERATION
The 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.

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.