ELECTRICAL FAN CONTROL OPERATION [AJ]
BME014000000T76
Normal condition
• When the engine coolant temperature is below Tw1, the duty ratio outputted from the PCM is 0%, causing the duty ratio outputted from the fan control module to also be 0% and the cooling fan is stopped.
• When the engine coolant temperature goes above Tw1, the duty ratio varies within the LO and HI (A/C off) positions in relation to the engine coolant temperature and the cooling fan operates accordingly.
• When the engine coolant temperature reaches approx. Tw2, the duty ratio is maintained in the HI (A/C is off) position until the engine coolant temperature goes above approx. Tw4.
• When the engine coolant temperature goes above Tw4, the duty ratio is MAX and the cooling fan operates at maximum speed.
A/C is in on condition
European (L.H.D.) specs.
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• When the A/C switch is on, the duty ratio is maintained in the HI (A/C is on) position until the engine coolant temperature goes above approx. Tw3.
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• When the engine coolant temperature goes above Tw3, the duty ratio varies within the HI (A/C is on) and HI (A/C is off) positions in relation to the engine coolant temperature.
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• When the A/C switch and refrigerant pressure switch (middle pressure) are on, regardless of the engine coolant temperature, the duty ratio outputted from the PCM is MAX, and the cooling fan operates at maximum speed.
Australian, General (L.H.D. R.H.D.) specs.
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• When the A/C switch is on, regardless of the engine coolant temperature, the duty ratio outputted from the PCM is MAX, and the cooling fan operates at maximum speed.
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1
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Engine coolant temperature
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2
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PCM output duty signal
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3
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Low
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4
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High (A/C is on)
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5
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High (A/C is off)
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6
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MAX
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7
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A/C is on (refrigerant pressure switch (middle pressure) is OFF)
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8
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A/C is on (refrigerant pressure switch (middle pressure) is ON)
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Battery Voltage Correction
• To prevent variation of cooling fan speed due to battery voltage fluctuation, the PCM adjusts the duty ratio and corrects the battery voltage to maintain the cooling fan at a constant speed and stabilize cooling efficiency.