Your Geo Tracker is equipped with an exhaust gas recirculation (EGR) system that works to improve emissions by reducing the formation of nitrous oxides. Your EGR valve and vacuum solenoid are both part of this system; however, they are separate parts with distinct functions.
Your EGR valve contains a spring-loaded diaphragm and is located near your intake manifold. When this unit receives ported vacuum, the diaphragm rises and allows exhaust gas to pass through a port and into your intake manifold.
Vacuum solenoids (EGR SV) are used with all EGR valves. The unit opens and closes to allow or prevent the engine vacuum from reaching your EGR valve. It is regulated by your vehicle’s EGR modulator. Depending on the year of your vehicle, it is located between the engine block and the firewall or mounted on the passenger-side wheel well.
When the modulator determines it is appropriate to reintroduce exhaust gas into your intake manifold, it signals your vacuum solenoid to open. This allows engine vacuum to flow through the modulator and to your EGR valve, where it causes the diaphragm to rise and exhaust gas to be directed into your intake manifold.
