MODES EGR Valve and Pneumatic Actuation Air pressure supplied by the EGR VPOD to the EGR actuator opens the butterfly valve. Once the EGR butterfly valve opens, the EGR flows through the EGR cooler and into the delivery pipe. 3-6 All information subject to change without notice. (Rev. April 2004) 7SE60 0404 Copyright © 2004 DETROIT DIESEL CORPORATION