What does an EGR Position Sensor do?
The EGR Position sensor detects the movement and position of the EGR valve pintle. The EGR Pressure sensor detects exhaust gas flow through the EGR passage. Where are these sensors located? Mechanical EGR valve position sensors are mounted on the top of the EGR valve. EGR pressure sensors will be located close to the EGR valve as the exhaust gas hose must be connected to the sensor as well as the valve. Will a malfunctioning EGR Position or Pressure Sensor illuminate the check engine light or affect vehicle operation? Yes, a failing sensor can illuminate the MIL, and may cause drivability problems. The signal is critical to the performance of the engine management system. Too much flow and the engine will stall or have a rough idle. Too little flow and emission gasses (especially NOx) will be elevated and detonation will occur. What are the common causes of failure? Typical failure is due to opens, shorts or intermittent signals. A DTC P0400 – P0408 can be set due to gas flow malfuncti
