I had a similar issue with my 08, but I kept noticing that the A/C would just quit. Then it progressed to a limp mode out of the blue and had it towed to the dealer. The first dealer couldn't find anything and sent me on the way. A week later it happened again and had it towed to another dealer. They ended up changing out the whole main electrical box (with the relays) on the drivers side under the hood. It's been 2 years now and 25,000 miles and no more problems.