1. The dual-passage cooling system is divided between the engine and heater radiator unit sub-assembly by the flow shutting valve (water valve). With this, coolant-flow through the engine is reduced when operating the heater before the engine has warmed up.

    2. By reducing the flow of engine coolant through the engine, warm up time is reduced which results in increased thermal efficiency and fuel economy.

      *1 Engine Water Pump Assembly *2 EGR Valve Assembly
      *3 Throttle Body Assembly *4 EGR Cooler Assembly
      *5 Heater Radiator Unit Sub-assembly *6 Water Valve (Closed)
      *7 Engine *8 Radiator Assembly
      *9 Thermostat (Closed) *10 Water Valve (Open)
      *11 Thermostat (Open) - -
      *a Engine Coolant Temperature: 5°C (41°F) or more and less than 65°C (149°F) *b Engine Coolant Temperature: 65°C (149°F) or more and 88°C (190.4°F) or less
      *c Engine Coolant Temperature: More than 88°C (190.4°F) - -