Follow below steps for set the maximum fan sped.
Press program key on display and go the service menu and press enter.
Select the hardware setting and go to evaporator fan with help of up/down key and press enter.
Select the fan speed and set value with the help of up/down key and press enter.
Press escape key two or three times to come back home screen.
Press program key on display and go the service menu and press enter.
Select the hardware setting and go to evaporator fan with help of up/down key and press enter.
Select the fan speed and set value with the help of up/down key and press enter.
Press escape key two or three times to come back home screen.