I bought my 07 Yukon in November. The remote start has not worked since I have had it. The spare fob did not work either. I just got back from the stealership. They said the spare fob was no good. So I bought a new one and had them reprogram both. They could not fix the issue with the rear hatch opening what they tries to do the remote start. They said they cleared the pc and let it relearn the program and still had the same issue. Now they say that they think it's a module on the starter that could be anywhere from $80-$200 and about 2 hrs labor. But they would have to run diagnostics first.
Has anybody figured out their issue yet?