Cooling System: Description and Operation

1. GENERAL
- The engine cooling system consists of a cross-f low radiator which features high heat-dissipation performance, an electric motor fan, an engine coolant pump, a thermostat, and an engine coolant temperature sensor.
- The reserve tank is designed to eliminate the need for replenishing coolant.
- On models without an air conditioner, the ECM sends an ON or OFF switch signal to the radiator fan in response to signals from the engine coolant temperature sensor. On models with an air conditioner, the ECM sends ON or OFF, and LO (Low) or HI (High) switch signals to the radiator main fan and sub fan in response to signals from the engine coolant temperature sensor, vehicle speed sensor 2 and A/C switch.











2. COOLING LINES
This cooling system operates in three steps depending on the temperature of the engine coolant flowing through the cooling circuit.
1st step ... With thermostat closed
At coolant temperature of below 76°C (169°F), the thermostat remains closed and the engine coolant flows through the bypass and heater circuits.
This permits the engine to warm up quickly.
2nd step ... With thermostat opened
When the engine coolant temperature is above 76 - 80°C (169 - 176°F), the thermostat opens and the coolant flows through the radiator where it is cooled.
3rd step ... With radiator fan operating
When the engine coolant temperature rises above 95°C (203°F), the ECM sends ON signal to the radiator fan in response to signal from the engine coolant temperature sensor and the radiator fan rotates.






TURBO MODEL

1. 1st step ... with thermostat closed At coolant temperature of below 76°C (169°F, the thermostat remains closed and the coolant flows through the bypass and heater circuits. This permits the engine to warm up quickly.
2. 2nd step ... with thermostat opened When the coolant temperature is above 76 - 80°C (169-176°F), the thermostat opens and the coolant flows through the radiator where it is cooled.
3. 3rd step ... With radiator fan operating When the coolant temperature rises above 95°C (203°F), the radiator fan switch is turned on and the radiator fan rotates.
4. When the engine is stopped after high-speed operations, vapor produced in the turbocharger cooling section is delivered from the coolant filler tank to the reservoir tank where it condenses back into water. Water is then absorbed by the coolant filler tank as the engine cools.