On 5/28/19 I filled my 2019 GMC Sierra denali at the local gas station. As usual I turned the vehicle off. After fueling, I started the vehicle and began pulling out of gas station. Upon exiting I lost all braking power and the pedal went to the floor. I was going approx. 5 mph. I pulled over and had to step on the brake pedal until it was on the floor with extreme force. The check engine light also appeared on the dashboard. At approx. 4:41pm I recieved an onstar email with an antilock brake problem. Email suggested I take the vehicle for service within 7 days. I had GMC roadside tow the truck from my home to the nearest dealer(staten island Buick GMC) I leased the vehicle from coleman Buick GMC and when I contacted them I was told they couldn't help and the dealer the truck was towed to is still GM. I also contacted GM customer service. Received a case # and waiting to be contacted. As per coleman the vehicle has recalls for a trailer brake module and park assist. As per si Buick GMC they could not find any computer codes. The hydraulic test showed no issues. They claim to have upgraded the computer and the truck was safe to drive as of 5/30. They want to test drive again on 5/31 and I assume I'll be asked to pick up my truck. I find this to be unacceptable and a major safety issue. Thankfully I was going 5mph when I lost full braking. I was told if the issue happens again to bring the truck back in for diagnostics and repair as needed. This safety issue can potentially cause physical injury and or prove to be fatal. Depending on technology to determine braking capacity is absurd. 2019 GMC Sierra also have electrical problems duly noted by customers. Forums also mark the same braking problems have occurred with other owners in different states. A recall should be issued for the safety of drivers, passengers and pedestrians! lives are at risk and a recall is needed!

- Staten Island, NY, USA

On April 2, 2019 I parked brefily for about 30 minutes. Upon re-entering my 2019 GMC Sierra truck with approximately 4500 miles and starting the engine I immediately received multiple warning messages on my dash panel. They were "service ESC" "service trailer brake", "brake system failure" "steering assist reduced" and to drive no faster than 62 mph. Previously prior to parking I had never had any problems whatsoever. I was in a location where I needed to go so I attempted to drive but found quickly that the brake pedel went all the way to the floor with very limited or basically no braking. The steering became very difficult with no apparent power assist. I drove it approximately two miles and got to a location where I could park. I turned the engine off and back on and the problem did not go away. I turned it off again and waited a couple of minutes and then heard an automated couple of clunk sounds from the front.. I started it up and everything was okay except the check engine light was on and stayed on the rest of evening. The next morning the check engine light was still on however about twenty minutes later I noticed it was off and everything has been fine since. I had planned to take it to the GMC dealer however with no problem showing now and from past experience with the dealerships I decided there was no need to schedule an appointment until the symptoms come back. I found on the internet later that there are numerous instances where this has happened to many other 2019 GMC Sierra owners. I feel that this is a extremely serious problem that needs immediate attention especially with the near total braking system failure!

- Owensboro, KY, USA

I am a heavy highway construction inspector for wvdoh and while working on I 81 sb in martinsburg, wv this morning around 2:00 am while performing my duties I attempted to pull out of my lane closure into traffic when my truck literally got stuck halfway out into live traffic. It was as if I was stomping on the brakes instead of giving it gas. Fortunately I reacted swiftly and put the truck in reverse to back into my lane closure preventing a collision with a tractor trailer traveling at speeds in excess of 55 mph. I was literally shaking when I realized how close of a call it actually was and that not only could I or the truck driver have been killed, but so could the workers on my job have been injured and/or killed. I had to have my truck towed back to my field office. For some reason the truck started driving properly again. There is definitely something wrong and it is extremely fortunate that no injuries occurred on my project. I did notice a post on this website explaining the very thing that happened to me this morning. This issue must be addressed immediately before people are killed. Thank you, [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Little Orleans, MD, USA

While driving my truck approximately 45 mph on a street, I heard the vehicle notification alarm sound, I looked down at the dash and had several warning lights illuminated:I had four messages: Service ESC service trailer brake brake system failure - 62 mph top speed steering assist reduced drive with care lights on dash that were illuminated ABS check engine brake traction control before I could read each warning light, a red stop light was approaching. I was at that time I pressed on the brakes and realized that my brakes were extremely spongey. I figured I only had about 10% braking power. With my two year old in the back seat, I pushed as hard as I could to stop my truck. Luckily, by the grace of god, I was able to stop my truck without rear ending the car in front of me. My truck was then towed to the dealership. I bought the truck 5 days prior. My truck has approximately 161 miles on it. The dealer told me the next day I needed a new master cylinder and hydro boost. Probably the absolute worse component to fail on the driver while the vehicle is in motion.

- La Habra, CA, USA

Rear wheel brakes unexpectedly lock up after driving over a hour or more

- Brooklyn, NY, USA

Have about 6000 miles on my 2019 GMC seirra denali 5.3. I've been experiencing a very troubling issue been to the dealership once already and had a hard time convincing them that something was wrong with the truck.every time I drive for long periods of time or idle for 10+ mins when I shift from park to drive I cannot go faster than 5 mph without the rear brakes locking up. I do not know if this is some kind of limp mode or what.

- Brooklyn, NY, USA