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.