Happened on Dec 2013 and Jan 3, 2014. Check engine light comes on, I call On-Star. They run test. They tell me I have water in my fuel. Take the car to the dealer service and they check the code which is water in the fuel. They check the fuel and no water in the fuel. They did more tests and then replaced the fuel sensor. Waiting to find out what the problem is now.

Dealer has treated me well.

Update from Feb 2, 2014: The 2nd time I was told that there was an indication of a small animal, mouse, and the mouse might have chewed on a wire. The dealer cleared the code and I was told they would need my car for a day. I set up an appointment.

Before the next appointment the check engine light came back on and being as I had an appointment with the dealer I did not call On-Stare as I assumed it was the same problem. The mechanic working on the car and checking the wires to the fuel tank found a bottle of dry gas in the trunk and stated that using that product could cause the fuel sensor to go bad and that I should never put an additive in the fuel. The owners manual states that a container of GM fuel treatment should be added to the fuel when the oil is changed. There was no proff that anything was added to the fuel. The check engine code was cleared.

Anyways, this morning, Sunday 02/02/14, when I started my car to return home from an erron I had a difficult time starting the engine as it would start and sputtor and stop. After several attempts it started and keep running. Called On-Star and they stated that I had a problem with the fuel sensor and I asked for the code and it was P0179 which is high voltage problem on the fuel sensor which is the same problem as before. A short someware.

Checking the Internet for the code P0179, it appears this is a common problem for GM and Ford products with Flex-Fuel. I will make an appointment with the dealer tomorrow and can not wait to hear what I am told this time.