Sentra XE L4-1.8L (QG18DE) (2000)
EGR Valve: Description and Operation
EGR volume control valve
The EGR volume control valve uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates
according to the output pulse signal of the PCM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens
or closes, changing the flow rate. When no change in the flow rate is needed, the PCM does not issue the pulse signal. A certain voltage signal is issued
so that the valve remains at that particular opening.