Exhaust Gas Recirculation System - Detroit Diesel MBE 900 Technician Manual

COMPONENTS PRELIMINARY
2.1.2

EXHAUST GAS RECIRCULATION SYSTEM

In general, the engine control system modulates the EGR rate of flow using parameters from the
various engine sensors to an optimize NOx and particulate levels in balance with the air fuel ratio.
The EGR system utilizes a combination of three EGR valves to control the exhaust gas
flow. See Figure 2-6. First there is an EGR shutoff valve on the hot side of the EGR cooler.
Secondly, there are reed valves mounted at the outlet of the EGR cooler. The third valve is an
electromagnetically actuated EGR control valve located downstream from the reed valves. The
system controls EGR flow during steady state and transient modes. EGR control is optimized for
maximum NOx control with consideration for particulate emission levels.
2-10
All information subject to change without notice. (Rev. 5/05)
7SE940 0505 Copyright © 2005 DETROIT DIESEL CORPORATION