EGR Valve Position Sensor: Description and Operation

PURPOSE
- To provide a signal used by the Powertrain Control Module (PCM) to indicate the amount of exhaust gases flowing into the engine.

OPERATION
- As the Exhaust Gas Recirculation (EGR) valve pintle lifts upward, it causes the EGR valve position sensor to move in direct proportion to the EGR valve opening.

- The EGR valve position sensor then converts the mechanical movement of the EGR valve pintle into an electric voltage signal which is relayed to the PCM.

- The PCM uses this feedback to adjust EGR vacuum regulator duty cycle to achieve the desired EGR flow and provides information to the PCM to detect EGR system failures.

CONSTRUCTION
The sensor is a linear potentiometer in which resistance varies with the EGR valve pintle movement.