I purchased my Sierra in 2021 and 2 weeks after purchase I got a warning for service stabilitrk and another for trailer brake system. This is very very annoying and also has my abs light on. My next issue is a code u510 for active grille shutter assembly. Please fix these issues as they are very common and unsafe. Not to mention as much ad I paid for this truck.

- Falmouth, KY, USA

Transmission started to shutter at 24000 miles. Dealer said couldn-??t find anything. ABS and Stabilitrack light came on at about 40,000 miles off and on. Both these problems could result in a crash. On freeway or streets. The display information/ radio has a mind of its own. Connects to any phone number or start the on star call and etc. it takes your attention off the road and can result in a crash.

- Houston, TX, USA

I kept getting a constant alert on my vehicle dash board that said "service trailer brake system" the beeping alert was quite literally constant and it covered up the digital speed odometer, every time I tried to acknowledge the alert it would just pop up and start beeping again. I searched online and quickly realized that this problem with the brake system has plagued GM vehicles for several years and I attempted to fix the issue myself by buying factory parts that other GM owners stated was the issue but it did not correct the issue. I ended up needing to take it to a GM service center and my vehicle was there for 2 business days and it ran me several hundred dollars to have GM fix the issue in the electrical brake system. Again according from online research this problem has plagued a large number of GM vehicles and it would be nice to see GM issue a recall and correct the issue so other people don't end up in the situation I was in.

- Fairmont , WV, USA

Have experience increased brake pedal effort, hard brake pedal, and/or potentially increased. stopping distance. The condition is more prevalent at low speed when softly applying the brakes. The Driver-??s Information Center, (DIC) -??Service brake assist-?? alert will activate. Extreme safety risk to myself and my children. Bulletin N182202780 & NT192268490 needs to be tied to this specific VIN Number as well.

- Athens , AL, USA

The electric power steering failed while accelerating into a turn from a stop at an intersection. The wheel was jerked from my hands, and the engine stalled, all electrical failed momentarily. Within a couple of seconds everything returned to normal. This has happened several times since I purchased this vehicle. Also the electrical power steering drops out quite often at low speeds, such as in parking lots. No warnings have ever been given. In May of 2021 the dealer replaced the steering rack, the problem has continued intermittently to this date. I have researched for recalls on this problem and found that GMC issued a recall for years 2014-2017, and am amazed that they could just declare the problem fixed, and leave such a dangerous problem unresolved!

- Palmetto Bay, FL, USA

Loss of dash electrical system and service stabillitrac warning came on when power was restored along with service suspension warning light. Headlights flicker and engine starts powering down before power comes back on by itself. If fuse to suspension is pulled or negative is removed and replaced, all warning lights go away.

- Goshen, IN, USA

Break system is making scratching noises as if it is a caliber breaking problem or a caliber piston problem, it is also setting off the trailer breaking system light on the dash as well as the trail traction control light.

- Cathedral City, CA, USA

The main harness under the truck, front to back. There was a separation from the conduit, wires exposed and were arcing. Truck would not start. I have since had it fixed. I just feel truck is not that old, to soon for a problem like this. And it cost a lot of money.

- Macomb , MI, USA

I purchased my 2018 GMC Sierra 1500 pickup truck new in 2018. To date it only has 28K miles on it. I have never used the trailer breaking system that it came equipped with. On 12/24/22 we were traveling to a family function for Christmas. The "service trailer break system" warning message came on and the chime chimed continuously until I got to my destination, about an hour away. This chime was very distracting and there was no way to turn it off. After arriving at my destination I turned the truck off hoping it was just a fluke. When I started the truck back up the "service trailer break system" warning light and chime continued. It continued for an hour on my way home. Again, this was very distracting and I was unable to focus 100% of my attention on the road and my driving. Thank fully I made it home okay. On 12/27/22 I took the truck to my mechanic to have him take a look. He said he has heard of this issue with these pickups. His diagnostic confirmed that the trailer breaking switch (on the dash) was functioning properly but said that the chassis control module was likely the culprit. He replaced the control module and it had to be programed by a factory technician. After this part was replaced the warning light or chime does not come on anymore. I have the defective part for inspection and the bill totaling $1191.86 for the repair upon request.

- Lake Oswego, OR, USA

While driving 35 miles per hour in the early morning hours I came to a 4-way intersection and applied the brakes slowly. Suddenly, I lost all power in the brakes and the steering wheel locked up. The lights, and stereo remained on, and my dash board display immediately showed a red check engine light. I immediately turn on my hazard lights, turned the ignition key off and tried to restart the truck. There was no clicking sounds. The truck would not start but the lights dimmed and the dash display now showed an intermittent yellow, flickering check engine light. After roughly 30 minutes while waiting for AAA to arrive I tried the ignition key and the truck started up with a red check engine light. Rather than attempting to drive I had AAA tow my vehicle to the Chevrolet dealership where I purchased the truck.

- Eugene, OR, USA

The light in the dashboard gose dark and it gives me a warning collision alert and the tiers they spin out of control when turning or when I I-??m driving I think it-??s the tiers they have a lot of tread still-??

- North Las Vegas, CA, USA

I was stopped at a fast food drive thru and then I tried to go to the next window and the truck wouldn-??t move at all it will just rev so I put it in parked turned off the truck and turn it back on put it on drive and was able to move for like 40 ft then it did it again so I had it towed to my home

- Seagoville , TX, USA

Trailer brake modulator on 2018 GMC Sierra does not consistently signal trail brakes to work when needed on our 7,500 pound RV trailer. GMC dealer eventually found that the battery cables were undersized as installed with the factory towing package on the 2018 GMC Sierra. The undersized battery cables do not consistently deliver adequate voltage to the trailer brake modulator on the GMC Sierra, so inconsistent electric brake function for our 7,500 pound RV trailer. Dealer had difficulty diagnosing the problem as being the wrong factory-installed battery cables to go with the factory-installed trailer towing package. So it cost us $1,600 to have the GMC dealer correct a problem caused by the GMC factory installing undersized battery cables. Fortunately, this did not result in a collision for us, but it might for someone else. Our 2018 GMC Sierra kept sending vague, randomly timed warnings to the dashboard to "Check Trailer Wiring." Very frightening, dangerous and costly (for us) mistake by GMC. Will the brakes work this time, or fail on the way home? Problem started in 2021 RV season, but took awhile for us to recognize the need to take to the GMC dealer for them to diagnose base cause. Took time for us to experiment changing trailer wiring connector on bumper and trailer brake control on the dash. Work for awhile, then fail. Work for awhile, then fail. Arrrrgh! Ask GMC to put more adequate battery cables on ALL their vehicles, please.

- Merrifield, MN, USA

SERVICE TRAILER BRAKE SYSTEM - warning

- Kansas City, MO, USA

-??Service- trailer brake system-?? light keeps coming on. It is super repetitive. It comes on about every 30 seconds. It-??s a loud beep that lasts quite a few seconds. Eventually, the beeping did not stop until the truck was stopped. Truck was just bought yesterday. Happens at any speed, even when stopped.

- Old Hickory, TN, USA

Im getting a service trailer brake system soon message on dash.

- Brooksville, FL, USA

The contact owns a 2018 GMC Sierra 1500. The contact stated while driving approximately 70 MPH, the trailer wiring harness system warning message was illuminated. The vehicle was taken to a local dealer where it was diagnosed with needing the wiring harness replaced; however, the vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 77,000.

- Boise, ID, USA

At 50,000 miles the "service trailer brake system" error message appears constantly due to factory defects and its very common. These trucks should be recalled everyone is in danger on the roads and its a very common problem. I have not taken it to the dealer because i should not have to pay for this very common problem, it should be recalled.

- Carolina Beach, NC, USA

The truck displayed warning lights for ABS, traction control, trailer brakes, and front park assist. Additionally speed control (cruise) did not function. This presented a safety issue. I took to dealer asap. They repaired by replacing left rear wheel speed sensor. Cost about $216. Appears to work correctly at this time.

- Mt. Vernon, IL, USA

Battery dies after 5days of not being driven. Battery continues to go dead, dealer states nothing is wrong. No repairs were made. Stranded 5 times with a dead battery

- Lapeer, MI, USA