Just bought 2010 Tahoe with only 41K on it! The car looks and rides great the only problem is driver’s seat as you know has three power directions “Forward – back. Up- down (back) up-Down (Front)”. The last position or move up-Down (Front) is not working. It keeps humming! I’ve searched and never find any similar issues. The dealer told me that they are selling the whole control which is 3 motors and mechanism cost around $500. I wish it is repairable. Any idea how to fix it or troubleshoot it?