Blower Fan Speed Control
WARNING: This page is about a different car, the 2010 Suzuki Kizashi. However, it is still accessible from the selected car via links, so may be relevant.
HVAC control module calculates the target blower fan speed based on signals from the temperature selector, inside air temperature sensor, outside air temperature sensor and sunload sensor. Comparing the calculation result with the current blower fan speed, HVAC control module controls the blower fan speed to the target level.