ELECTRICAL FAN CONTROL OPERATION [MZR-CD (RF Turbo)]
BME014000000T43
Normal condition
• When the engine coolant temperature is less than TW1, the duty ratio output from the PCM is 0%, causing the duty ratio output from the fan control module to also be 0% and the main fan is stopped.
• When the engine coolant temperature goes above TW1, the duty ratio varies within LO and HI2 in relation to the engine coolant temperature and the main fan operates accordingly.
• When the engine coolant temperature reaches approx. TW3, the duty ratio is maintained at HI2 until the engine coolant temperature goes above approx. TW4.
• When the engine coolant temperature goes above TW4, the duty ratio is MAX and the main fan operates at maximum speed.
A/C is on condition
• When the A/C switch is on, the duty ratio is maintained at HI1 until the engine coolant temperature goes above approx. TW2.
• When the engine coolant temperature goes above TW2, the duty ratio varies in relation to the engine coolant temperature.
• When the A/C switch and refrigerant pressure switch (middle) are on, regardless of the engine coolant temperature, the duty ratio output from the PCM is MAX, and the main fan operates at maximum speed.
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1
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Engine coolant temperature (°C {°F})
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2
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PCM output duty signal (%)
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3
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A/C switch is on
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4
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A/C switch and refrigerant pressure switch (middle) are on
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Battery Voltage Correction
• To prevent variation of main fan speed due to battery voltage fluctuation, the PCM adjusts the duty ratio and corrects the battery voltage to maintain the main fan at a constant speed and stabilize cooling efficiency.