2006 GMC Envoy Check Engine Light Code

My problems started with getting some cheap gas from a station I normally don't go to. My Envoy jerks when I reach 15 mph, then it runs fine. My fuel gauge sensor went out and I got that replaced. They say bad gas could of started all of my problems. I waited till my gas got low and put the 93 gas in with some gas cleaner, but now I am getting a new code P0700 Transmission Control System Malfunction. What does this mean, and would this be covered under my Powertrain 100,000 mile warenty?

[img:802d7bb60a]http://www.2carpros.com/forum/automotive_pictures/156778_GMC_ENVOY_1.jpg[/img:802d7bb60a]