Nubira SX Hatchback L4-2.0L DOHC D-TEC MFI (1999)
Radiator Cooling Fan Motor: Description and Operation
ELECTRIC COOLING FAN
Caution: Keep hands, tools, and clothing away from the engine cooling fans to help prevent personal injury This fan is electric and can turn
on whether or not the engine is running.
Caution: If a fan blade is bent or damaged in any way, no attempt should be made to repair or reuse the damaged part. A bent or damaged
fan assembly should always be replaced with a new one. Failure to do so can result in personal injury.
The cooling fans are mounted behind the radiator in the engine compartment. The electric cooling fans increase the flow of air across the radiator fins
and across the condenser on air conditioned (A/C) equipped vehicles. This helps to speed cooling when the vehicle is at idle or moving at low speeds.
The main fan size is 300 mm (11.8 inches) in diameter with five blades to aid the air flow through the radiator and the condenser. An electric motor
attached to the radiator support drives the fan.
A/C models have two fans - the main fan and the auxiliary fan. The auxiliary fan is 300 mm (11.8 inches) in diameter.
A/C OFF or Non-A/C Model
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The cooling fans are actuated by the powertrain control module (PCM)/engine control module (ECM) using a low-speed cooling fan relay and a
high-speed cooling fan relay. On A/C-equipped vehicles, a series/ parallel cooling fan relay is also used.
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The PCM/ECM will turn the cooling fans on at low speed when the coolant temperature reaches 93°C (199°F) and at high speed when the coolant
temperature reaches 97°C (207°F).
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The PCM/ECM will change the cooling fans from high speed to low speed at 94°C (201°F) and will turn the cooling fans off at 90°C (194°F).
A/C ON
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The PCM/ECM will turn the cooling fans on at low speed when the A/C system is on. The PCM/ECM will change to high speed when the coolant
temperature reaches 115°C (239°F) or the high side A/C pressure reaches 1 882 kPa (273 psi).
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The cooling fans will return to low speed when the coolant temperature reaches 112°C (234° F) and the high side A/C pressure reaches 1 448 kPa
(210 psi).
