EGR Valve

EGR valve in the DPFE EGR system is a conventional, vacuum actuated EGR valve. The valve increases or decreases flow of exhaust gas recirculation. As vacuum applied to EGR valve diaphragm overcomes spring force, valve begins to open. As vacuum signal weakens, at 1.6 in. Hg (5.4 kPa) or less, spring force closes valve. EGR valve is fully open at about 4.5 in. Hg (15 kPa). Since EGR flow requirement varies greatly, providing service specifications on flow rate is impractical. The OBD-II system monitors EGR valve function and triggers a DTC if test criteria is not met. EGR valve flow rate is not measured directly as part of field diagnostic procedures.