I have a 2012 Ford Edge Limited that had the same problem with the mystical, surging CC system.  And sometimes the 4-way flashers came on randomly too.  All else worked fine.   When the AC climbed to max (this all happened during the summer) I could wait 5-10 sec and use the minus (-) button on the dash to turn down the AC but often it would jump back up again.  Eventually, the + or - on the dash wasn't reliable.  However, the + or - worked on the LCD panel OR via the controls on the steering column.  I removed the Front Control Interface Module (FCIM) to try to repair it but nothing changed.    Ford wanted $140 to diagnose my problem, $758 for a FCIM and $280 to install and program it.  Based on the help I found on this blog and other places, I decided to find a used FCIM.  My 2012 Edge FCIM has engineering no. CT4T-18A802-CG.  I located a FCIM with engineering no. BT4T-18A802-CL in a 2011 Limited Ford Edge.  Before I bought it ($31.00) I called United Radio in NY State.  They seem to be the sole place to get these repaired.  They are great and helpful.  I talked to the technician who does the actual repairs on all the FCIMs.  He explained that he would rebuild mine for $300.  You ship it to him and return shipping is free.  But he also told me that any Limited FCIM that starts with a B is a 2011 and starting with a C is a 2012.  And the 2nd last character had to be a C to indicate that it supports heated seats (heated seats are stock on the Limited 2011, 2012, and 2013, and maybe more). Today I visited the boneyard that had the 2011 Limited Edge.  I bought the part, installed it in 30 min (while in the parking lot), and drove away a happy buyer.  It worked 100% and I get to keep my old FCIM.  Now I have a spare that I can send to United Radio in case the used one fails.  BTW, a new or rebuilt FCIM has to be programmed.  But one that comes from a similar used Edge is ready to go because it's programmed at the factory.