Whirlpool French Door Fridge at 55 degrees, Freezer seems fine

My french door model Whirlpool (freezer on bottom) is 3 years old and is malfunctioning. The freezer appears to be doing fine, but the refrigerator has stopped cooling (55 degrees).

I live over 6 hours away from the nearest qualified repairman, or store to replace the unit, so I am interested in finding and fixing the issue. Any information anybody would be willing to share would be greatly appreciated.

Thanks,
Bart