The illustration shows the cooling system layout.
The cooling system uses deflectors, air baffles and air seals to increase cooling system capability. Deflectors are installed under the vehicle to redirect airflow beneath the vehicle and through the radiator to increase engine cooling. Air baffles are also used to direct airflow through the radiator and increase cooling capability. Seals are used to prevent air from bypassing the radiator and air conditioning condenser. The seals also prevent the recirculation of hot air for improved hot weather cooling and air conditioning condenser performance.
Cooling Fan Operation
The engine control unit (ECU) controls the fan speed by sending a variable signal to the cooling fan control module. The cooling fan control module varies the speed of the fan motor in relation to the signal.
The ECU commands the fan ON under the following conditions:
Fan Control During Engine Operation (Engine ON)
- Fixed 94% duty cycle is commanded when the following conditions are met:
- Variable duty cycle from 15–95% is commanded when:
Fan Control During After-run (Engine OFF)
- Fixed 36% duty cycle commanded after shutdown when the engine coolant temperature at shutdown is greater 101°C
- Fixed 60% duty cycle commanded after shutdown when the engine coolant temperature at shutdown is greater than 108°C
- Fan commanded OFF during after-run when:
Engine Coolant Telltale - Low Coolant Level
The low coolant telltale is a warning message displayed in the information display at the instrument assembly.
“LOW COOLANT” is displayed when any of the following occurs:
- The body control module (BCM) detects a low coolant level condition for at least 30 seconds
- The driver information centre (DIC) performs the displays test at the start of each ignition cycle. “LOW COOLANT” is displayed for approximately 3 seconds
Coolant
The engine coolant is a solution made up of a 50-50 mixture of approved coolant and potable water.