General
The EGR system consists of a valve, vacuum regulator, tube and a differential pressure feedback EGR sensor.The EGR system recycles measured quantities of exhaust gas back through the engine where they mix with the incoming air/fuel charge.
The powertrain control module controls the vacuum regulator valve with grounding pulses. This regulates the quantity and duration of the vacuum signal supplied to the EGR valve therefore the valve lift and opening time are controlled.
The differential pressure feedback EGR sensor provides the powertrain control module with data relating to the exact quantity of exhaust gas being recirculated by measuring the differential pressure across a calibrated orifice in the supply hose. Therefore, closed loop control is achieved.