heater controls on 2004 Hyundai Santa Fe

ok the heater controls are digital and unless i have the temp set at 90 cold air comes out of the vents it don't matter if it is on 75 or 89 it is cold untill i put it to the 90 setting anybody have any idea's or suggestions ? could it be the heater controls or possibly the body control module ?

Asked by for the 2004 Hyundai Santa Fe
I am currently experiencing the same problem. Some times, cold air is blowing and we have to turn it to 90 to get heat. If we drop it down 3 degrees, it reverts back to cold air. Mine is at this moment being looked at by a garage. Hyundai dealership nearby said it would be $92.00 diagnostics, + $150-200 dollars for labor and then it depending on what parts need replaced. I cannot believe that this unit is only covered by the 5/60 warranty instead of the 10/100. Little bit of false advertising on Hyundai's part when they were using the 10/100 warranty as a positive in commercials, not mentioning that it is limited.