Thermostat Normally Open
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
With the thermostat normally open the coolant passes from the coolant pump-via a passage in the cylinder block-up through the cylinder head-via the throttle body (preheating) to the thermostat housing-and through the thermostat housing's two outlets. The coolant passing out through the lower outlet goes back to the coolant pump via the heat exchanger. The coolant passing through the thermostat's upper outlet goes directly to the radiator and from there to the coolant pump.