bowtie2007

Mine does this as well. In addition, when stopped, it feels like I am on an overpass and the bridge is shaking. It is a very rhythmic bouncing. I first noticed the issue after bringing the truck to the dealer for a DPF reprogramming recall. On another forum, people are saying it needs an injector small quantity reset but the ones who took it to a dealer for that got mixed results. I have not had a chance to get mine to a dealer for the issue.

I went through the same thing. I finally bought the GM specific X431 Launch bi-directional scan tool. It is currently on Amazon for $180 with a $40 off coupon bringing it down to $140. With that tool, I was able to reset my brake pad life. I would rather pay that and have a new toy than pay the dealer to do it.

I have a 2020 with the same issue. The brakes were squealing, moaning, roaring, and whatever other annoying sounds you can think of when stopping at slow speeds. And this was with cold or hot brakes, it did not matter. A drive thru was very embarrassing. My dealer changed my brakes around 20k miles based on a TSB but the new brakes were not any better. After dealing with the noisy brakes for 68k miles, I finally got fed up a couple months ago and changed all the brake pads to the Powerstop z36 towing pads. I have put almost 3k on those pads and not even a little squeak. I normally only buy OEM parts but do yourself a favor and ditch the GM pads, you'll be glad you did! And it is definitely an issue. Here is the 7 page post from another person.

I have a friend that also has a 2020 Sierra diesel and he asked me about the bouncing feeling following the DPF recall. I'm not happy with the reprogramming from that recall.

I have a 2020 Sierra 2500 diesel with 54,000 miles. For the last several months, my truck has developed a subtle rhythmic bouncing when idling. Being in drive or park does not make a difference. I've also noticed a surging when there is constant throttle around 25 to 35mph. The RPMs do not seem to move with the surging. If I let off the throttle or give more throttle, it stops. Is anyone else experiencing these issues?

Many owners have had this leak. The frame at the top of the window develops cracks which begin to leak. I had a 2019 Sierra 1500 and now have a 2020 Sierra 2500. Both windows leaked. There is a TSB and a very long thread regarding the topic under the 1500 thread.

There is a TSB on that issue. I was having the same problem and this fixed it. I had to tell the dealer about it.

After a couple months, the shifting became less aggressive and the MPGs are similar at slower speeds. The biggest difference I noticed now is driving above 70mph. I used to get about 20 mpg driving 75mph. At those speeds, I'm lucky to get 18 now. The new programming seems to be set for optimal mpg between 55 and 65 mph.

I got the recall done a couple weeks ago and there is a noticeable difference in the way it drives. It operates like it is in a constant regen cycle. It holds lower gears more often, keeping the RPMs higher and lowering my fuel economy. It is also more aggressive on the downshifting when I let off the accelerator. This is how it felt during the regen cycle prior to the tcm update, except it happens all the time now. I verified with a scanner that I am not in a regen, i was at about 85% soot level. Stop and go traffic around town would get me around 14 to 15mpg before. Now, I am getting 11 to 12. On the highway at about 70mph, I was easily getting 20mpg or more. Now, it is more like 18 to 19mpg. I hope the transmission is still trying to figure things out and will get better.

I did not think about NHTSA but I have filed a complaint with the BBB and FTC claiming a violation of the written warranty. I don't know how they can have a cracked window frame and just put sealant over the cracks instead of a replacement part. I don't know anything about how class actions lawsuits work or I may have tried that. tbully, I'm glad you got the replacement window instead of the sealant!

The rear sliding glass window of my 2020 GMC Sierra 2500 developed a leak in January of 2021. It caused water to saturate the carpet under the rear seats and allowed water to enter the rear seatback storage compartments. TSB 18-NA-383 states the cause is from cracks developing in the rear sliding window plastic upper rail glass guide and the solution instructs dealers to put seam sealant over the cracks. Skip forward a year later and 3,000 miles out of factory warranty. The sealant failed and the window was leaking again. GM initially refused to pay anything and the dealer wanted $1,382.70 because they stated I needed a full rear window replacement. Extended warranty wouldn't cover it because it was not a mechanical breakdown. After a many calls to GM customer assistance, they agreed to cover 70% leaving me to still pay $414. This window leak is not isolated to just a few. I had a 2019 GMC Sierra 1500 in which the rear window leaked before I traded. A friend of mine has a 2020 GMC Sierra 2500 and his window is leaking. GM will try to put a bandage on the window cracks in the form of sealant instead of actually replacing the defective window. Many of the people in the forums report that the sealant does not last as was the case with mine. If you are unlucky enough to fall outside of warranty when the sealant fails, GM will not cover anything without a fight.

The rear sliding glass window of my 2020 GMC Sierra 2500 developed a leak in January of 2021. It caused water to saturate the carpet under the rear seats and allowed water to enter the rear seatback storage compartments. TSB 18-NA-383 states the cause is from cracks developing in the rear sliding window plastic upper rail glass guide and the solution instructs dealers to put seam sealant over the cracks. Skip forward a year later and 3,000 miles out of factory warranty. The sealant failed and the window was leaking again. GM initially refused to pay anything and the dealer wanted $1,382.70 because they stated I needed a full rear window replacement. Extended warranty wouldn't cover it because it was not a mechanical breakdown. After a many calls to GM customer assistance, they agreed to cover 70% leaving me to still pay $414. This window leak is not isolated to just a few. I had a 2019 GMC Sierra 1500 in which the rear window leaked before I traded. A friend of mine has a 2020 GMC Sierra 2500 and his window is leaking. There are hundreds of pages of forums in the 1500 forums regarding a leaking rear window. GM will try to put a bandage on the window cracks in the form of sealant instead of actually replacing the defective window. Many of the people in the forums report that the sealant does not last as was the case with mine. If you are unlucky enough to fall outside of warranty when the sealant fails, GM will not cover anything without a fight.

That could be from the window. Both my compartments had water in them from my window leaking.

I also got def quality warnings with blue platinum. Stopped using it and the messages haven't returned.

To comment on the 2500s, I came over to this forum because there is way more information on the leaking windows. I have a 2020 Sierra 2500 and the rear window first started leaking at 20,000 miles. The dealership sealed it but a year later, it has started leaking again. The sealant does not appear to be a long term fix.