general problems of the 2020 GMC Sierra 2500

Tailgate unlatches unexpectedly. Has happened while parked and while driving. Almost caused accident to others.

Cracks in the rear sliding window plastic upper rail glass guide causing rear window leaking water and causing mold from water leaking. GMC has a service bulletin number 18-na-383 knowing of this issue and not telling customers purchasing the GMC vehicle. The service bulletin was released in 2019 before purchasing the truck and they still didn't inform the customers. My child rides in the back in a car seat and now has been breathing in this mold and mildew for how long. I have had my vehicle in with titus will GMC in olympia multiple times for service and inspection of various recalls and still didn't inform me of this issue.

I have a notice of a recall for the transmission control module and I took it to a GMC dealership and they are refusing to fix it. The transmission will not shift so I am unable to drive it.

Odi # 11646185 my truck on [xxx] leaked transmission coolant from the jumper line leak( which this part is recalled but not for my VIN #) $400. 61 dollars and left me stranded in the middle of the highway and had to be towed. After the repair and checking the transmission was discovered it was ruined because of the leak. So now I have to have a new transmission installed at jennings in beardstown IL to the cost of $7363. 39. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My truck had been sitting idling for about 20 minutes on a job site on flat level ground. I turn around for whatever reason and my truck is driving forward with on one in it but my dog. The truck ran into an out rigger on my crane. I had 3 of my employees there that witnessed this happen. I got into my truck and the shifter was in drive. Somehow my dog was able to shift my truck into drive from park while it was sitting idle. I have 3 eye witnesses as well as pictures of the incident. I have pictures but was no able to upload them to they portal.

I have a 5th wheel with solar and my brake controler stops working periodically. I have a case# with gm 9-13676268071. I also hjave an extended warranty with gm and it's not covered due to my VIN# not being on a bullentin# 23-na-149. Gm also has a customer satisfaction progream # n232414840 and still won't cover it. This is a major safety item and concern for me.

Well, we ended up having a problem with our transmission in our 2020 truck. I am the wife and I was driving down the highway and all of a sudden the truck started bucking and went down to 35 mph. I was in a middle lane on the highway when this happened which was very scary! then I was stranded along side the highway until I could get help. Here we found that our transmission went out already only after four years, which is crazy. Very crazy! we bought this truck because we were told with the weight of this truck and all that it would pull out 42 foot fifth wheel we have. So of course we did use this truck to pull our trailer and now four years later we have been without a truck because we cannot even find a transmission with our transmission code of omef. Now today we found a possibility which is going to cost $7000 which is love ludacris! we buy a $65,000 truck just for years ago and now had to put $7000 out for a transmission. Is there anything we can do to rectify this situation??.

Rear sliding window leak and has saturated seat and carpet causing an unhealthy environment. Spoke with dealer and was told it is a design flaw and repairs are not covered under extended warranty. I was also told it is only a temporary fix and “ leak will reoccur”. I only realized of the problem when soap residue was seen on the inside of the widow. Dealer gave estimate of repair.

When towing a trailer a notice to service trailer brakes comes on and the trailer brakes are disabled.

1. The engine block heater sparked and created a small flash underneath the truck. It can be inspected whenever you would like. 2. Electric spark/fire 3. The problem has not been reproduced nor inspected by the dealer. I would not dare to plug it back in. 4. There were not any warning messages. It happened the first time the engine block heater was plugged in. February of 2022.

Def emission system failure. Total component breakdown requiring replacement. Parts unavailable.

Tailgate fell down when I had a trailer hooked up. I was parked, then backed up the trailer. Tailgate came down on the jack and scratched the tailgate. There is a recall on some trucks but mine says no recall. Sounds like same issue.

Part #19419266 tonneau was installed 07/16/2020 and leaks terrible in the rain.

The front park assist sensors on this truck do not operate as intended, or as on prior years or as on other vehicles. The sensors did not pick up parking bollards in front of a convenience store and resulted in a minor ding that cost over $1300 to repair. When bumper was repaired the service person said sensors were fixed, yet, to his surprise, we were able to inch up to a car directly intersecting the front of the car and it did not pick it up. I did a similar test with a brand new/unsold vehicle on dealer lot ind it failed to sense the large truck directly in front of it. This I believe can be a very dangerous safety issue as the truck hood sits very high impeding viability and a small person or pet can easily go undetected. These vehicles has also had numerous recalls including one for the possibility of the hood flying open while operating. I have sold the truck as all of these issues have devalued the vehicle, it remains unsafe and gm response has been less than favorable.