EGR Valve Position Sensor: Description and Operation

EGR valve position sensor:

The EGR Valve Position (EVP) sensor is a linear potentiometer mounted on top of the EGR valve. The EVP Sensor returns a voltage signal to the Electronic Control Assembly (ECA) indicating whether the valve is opened, closed, or somewhere in between. The voltage signal is in direct relation with the valves movement.

An example of this relationship is as follows:

EGR OPENING VOLTAGES

BLACK SENSOR GRAY SENSOR
0% .90 volts .35 volts
10% 1.25 volts .75 volts
20% 1.65 volts 1.10 volts
30% 1.95 volts 1.45 volts
40% 2.30 volts 1.80 volts
50% 2.65 volts 2.15 volts
60% 3.00 volts 2.50 volts
70% 3.35 volts 2.85 volts
80% 3.70 volts 3.20 volts
90% 4.05 volts 3.55 volts
100% 4.40 volts 3.90 volts


NOTE: EGR closed position is very important. Timing is retarded if EGR flow is low.