I am the unfortunate owner of a 2009 Yukon XL, it currently has 49,500 miles on it and in the last 6 months has been in at least once with problems. This is the short list:
1) Door module of course as you see that many times
2) hot air coming out of drivers side vents and a/c on passenger.
3) oil sensor model and remember this one it enabled us to find out that bulletins exist concerning oil consumption. The valve covers do not allow the oil to drop back down to the engine
4) after we got that done and the repair did not work it tossed another code about emission module and it then had metal in the oil
5) the valves rings had to be replaced.
6) 3 more codes in shop today!
I just bought our 2009 Denali and so far it's been a great experience. The power behind the wheel and the towing abilities are going to benefit us, my family and friends, as we like to be out doors and enjoy hauling my camping trailer every where we go. GREAT vehicle.
We purchase a 2009 GMC Yukon Denali Oct. 2009 to replace our 2003 Chevy Suburban, which was an incredibly reliable vehicle. What a difference the GMC Denali makes. Superior ride, more hp and even better fuel mileage, getting 18.1 city and unbelievable 21.6 highway at 78 MPH. Strongly recommend this vehicle to anyone that loves to be comfortable. It comes loaded with more than you can imagine. We just love it.
I always drove Toyota and Hondas but after long research bought Yukon 2009. I am really impressed by smooth drive. We have two kids and our parents often travel with us, its been great fun in Yukon. DVD quality is great. I wish they had LATCH for car seat at all seating places in middle and third row. There are no front latches in 3rd row and has only one back latch. You might have tough time fitting two car seat in 3rd row. I get about 14.5 mpg at 1000 mi. Over all, not going back to Honda and toyota at all.
We've got the Yukon Denali and it has been incredibly reliable with decent gas mileage considering it's size. To date, I've put 47,000 miles on the rig, and other than a recent brake job have done nothing but change the oil. Those that complain about GM and these trucks haven't owned one. I have been pleasantly surprised by the lack of repairs required. Biggest complaint would be lack of reclining seats in second row (we've got the bench) and slow to respond reverse camera - seems to take forever sometimes. Cheers