Exhaust Gas Recirculation: Description and Operation

The ECU contains memories for ideal EGR valve lifts for varying operating conditions. The EGR valve lift sensor detects the amount of EGR valve lift and sends the information to the ECU. The ECU then compares it with the ideal EGR valve lift which is determined by data sent from the other sensors. If there is any difference between the two, the ECU triggers the EGR control solenoid valve to reduce vacuum applied to the EGR valve.