Air conditioning failed. This needs to be documented. Not a "safety" issue at first, but with pets and kids it can become one. I have owned this truck for a little over a year. I bought it used for over $35,000. It had 50,000 miles on it. My first summer the A/C worked, but not great. Last week I tried to use my A/C and nothing but hot air. I thought it was strange being only a couple years old. I paid to get the freon re-charged. The freon leaked out after 2 days and A/C stopped working. I had to schedule a diagnostic appointment for $118. I have done research and it sounds like I should be looking at a repair costing anywhere from $800 to $2,000. There have been several online complaints, along with a class action law suit to cover this problem. The issue is that it is a "luxury item" not a safety item. It needs to be documented on all websites that this is an issue, so consumers can be informed. This can be dangerous when traveling with young children and pets. The air that comes out of the vents is extremely hot. In hot temperatures this can become dangerous.

- Hudson, MA, USA

Ac condenser failed at 40000 miles. GM has extended warranties for their SUVS related to this common and known issue, however has not included their trucks in the warranty extension. The faulty condenser is the same exact part for the trucks as the SUVS and as such should be included as well.

- West Barnstable, MA, USA

Since buying the truck new in 2016 it had a vibration, which got worse as you increased speed, at highway speed, 65-75 mph the vibration is so bad it was making me nauseous. I have taken it to the dealer several times, first balanced the tires and said everything was normal, truck still vibrating. Several more trips to the dealer with the same result.

- Monroe Township, NJ, USA

I was driving down road and back drivers side window exploded. My granddaughters were sitting in their car seats and were showered with glass. The window literally blew up. I called dealer, he said he's never heard of such a problem. I found several complaints on my GMC forum page and wxyz 7 in detroit, mi. Has run stories on this problem.

- Rhinelander, WI, USA

Constant vibration and or shake at speeds between 60-70 mph. This issue is commonly referred to as the "Chevy shake" this issue has been existing since first purchasing this vehicle. I addressed the concern with the dealership during multiple visits for service. As this was my first full size truck, I wasn't sure what to expect regarding how the vehicle would ride at highway speeds. I was told by the service department that the vehicle was in tolerance in regards to how it rode and the constant vibration. So I excepted this as being the norm and went ahead to add some modifications to my truck. Since the initial complaint the service department has since turned over most of their staff and added people willing to address and acknowledge that my vehicle indeed has this vibration/shake issue. Due to the modifications made they will not address or attempt to correct this issue. Had I pressed the issue in the beginning and not accepted what these so called professionals had told me to be acceptable maybe I wouldn't be in this predicament. My vehicle has also been in for numerous bucket seat issues from sagging and poor seat support. Everything described here is factual as I have all the service records and history with the same GMC dealership and service department in regards to these problems. Long story short, these issues have made long distance trips almost unbearable between the constant shaking and poor seat support.

- Orchard Park, NY, USA

Ac condendor. I am having to replace the ac condendor on a 2 year old truck at a cost of over $1000. Truck is just over dealer certified warranty by 6,000 miles with 54000 miles. After being told by dealer that this was a known issue and researching online, it appears that is a costly repair that is affect large numbers of owners. GM has offered extended warranty on similar vehicle that have this engine and condendor setup but not included the Sierra. Appears to be a known manufacturer defect that they are not covering.

- Rome, GA, USA

(1) the truck hesitates and the engine almost shuts off like it's not getting enough gas, it does this for about the first 45 mins. Of startup. (2) the battery has been replaced for the second time and even with a new battery it sounds like it's barely got enough power to start the engine

- Johns Island, SC, USA

We have violent shimmy/shaking issues with our truck and have since we got it brand new. We have taken it to the dealer 5 times and even had the dealer witness the shaking the last time while on a test drive. They replaced the torque converter, rebalanced the wheels, and rotated the tires and the problem continues to happen repeatedly. We do not feel safe driving this truck any longer as it happens at speeds above 40mph. The dealer says they can't fix it if they don't know what is wrong.

- Raytown, MO, USA

I have a 2016 GMC Sierra 1500 5.3L. I've brought the truck down to the dealer 4 times now because the ac doesn't blow cold air. The ac stopped working again this week with the truck only having 2,800 miles on it. I called GMC directly (not the dealer) because I don't want to bring the truck down to the dealer for the 5th time for the same issue. It's 85+ degrees now where I live and driving without ac is unbearable, especially when in traffic. GM sent me an E-mail informing me the ac condenser is faulty by design and a 'redesign' has been created. The part is on "national back order" with no eta. They said it could be 4-6 weeks which means driving my truck without ac is very uncomfortable and not an option with children in the truck who can't withstand the heat. I'm reading on various forums that people have been waiting since March (4 months) for the new condenser to come in.

- Westborough, MA, USA

Vehicle has a vibration that gets worse as speed increases.GM not being able to determine the origin of the problem has said it is not a safety issue.the very fact that they cannot find the origin makes it a potential safety issue. After much diagnostic work and parts replacement still no answer.

- Calhoun, GA, USA

A week after purchasing my new 2016 GMC Sierra denali 1500 short bed I began noticing a strong vibration/shake that could be felt while in motion at highway speeds between 75-80mph. The flatter the road the stronger the vibration can be felt at these speeds. I have brought it in twice to the dealership I bought it from and once to another dealership yielding no fix to the problem. Actually, I have been told there is no problem and that is how the truck rides. I have also been told my expectations for a pickup truck "unrealistic." When the front and passenger seats physically shake at the speeds mentioned I find it very hard to believe that there is no issue with the vehicle and that my expectation should be considered unrealistic. Driving the truck long distances on the highway is unpleasant at best creating at times feelings of nausea. I have zero confidence the issue will be addressed, but wanted to air my complaint for other potential buyers. This truck is supposed to be the top of the line and I absolutely regret buying it with this persistent problem present that nobody wants to address.

- West Islip, NY, USA