Cooling Circuits
WARNING: This page is about a different car, the 2004 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
The cooling system operates in three different phases depending on the temperature of the engine coolant.
- 1st phase (thermostat closed)
When the engine coolant temperature is below 76°C (169°F), the thermostat remains closed. The coolant flows through the bypass and heater circuits. This permits the engine to warm up quickly.
- 2nd phase (thermostat open)
When the engine coolant temperature is above 76-80°C (169-176°F), the thermostat opens. The coolant flows through the radiator where it is cooled.
- 3rd phase (thermostat open and radiator fan operating)
When the engine coolant temperature sensor sends a signal indicating a temperature above 95°C (203°F) to the ECM, it causes the radiator fan (or fans) to operate.