COMPONENTS EGR Valve The valve position is controlled by DDEC. The ECM continuously monitors all engine operation modes and performs self diagnostic checks of RPM, load, altitude, air temperature, etc. and uses this information to determine the valve position. When the EGR valve is closed, exhaust flow from the exhaust manifold, past the turbine wheel in the turbocharger and out the exhaust system, in the traditional way. When the valve is open, some of the exhaust gas is directed into the EGR cooler, through the delivery pipe and into the intake manifold. EGR Valve Actuator Figure 2-8 EGR Valve Actuator The EGR valve regulates the EGR flow rate via air pressure input from the VPOD.
The EGR valve has the following components (see Figure 2-9): 2-8 All information subject to change without notice. (Rev. April 2004) 7SE60 0404 Copyright © 2004 DETROIT DIESEL CORPORATION