THERMO Valve
Thermo valve senses engine coolant temperature, and allows or denies vacuum to EGR valve, depending on engine temperature. Below 122°F (50°C) on 2.0L engines or 131°F (55°C) on 2.3L engines, thermo valve is closed and no vacuum from intake manifold reaches EGR valve. Above these temperatures, valve is open and EGR occurs.
NOTE:
On California vehicles with 2.0L, 2 thermo valves are used, one of which is connected to the air control valve and not the EGR. Be sure to inspect hose routing diagrams in this article.