Exhaust Gas Recirculation System - Honda Civic 1998 Service Manual

Exhaust Gas Recirculation {EGR) System (Dl6Y5 enginel
Description
The EGR system is designed to reduce oxides ot nitrogen emissions {NOx) by recirculating exhaust gas through the EGR
valve and the intake manifold into the combustion chambers. lt is composed of the EGR valve, EGR vacuum control valve,
EGR control solenoid valve, ECM and various sensors.
The ECM contains memories for ideal EGR valve litts for varying operating conditions. The EGR valve lift sensor detects
the amount of EGR valve lift and sends the intormation to the ECM. The ECM then compares it with the ideal EGR valve lift
which is determined by signals sent from the other sensors, lf there is any difference between the two, the ECM cuts cur-
rent to the EGR control solenoid valve to reduce vacuum aoolied to the EGR valve.
EGR CONTROL
cVT.
SOLENOIO VALVE
BLK
4
EGR VALVE LIFT SENSOR
BLK
I
1 -16 9