2018 GMC Sierra 1500 ELECTRICAL SYSTEM,SERVICE BRAKES
Owner-reported problems and safety issues filed with NHTSA. Review common failures, severity levels, and complaint trends over time.
Complaint Timeline
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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.
The brakes sometimes lock up after use, or don’t disengage ( on one side) and the truck swerves ( steering wheel turns to the right ) into the next lane. I have to over correct and you can hear the brakes squeal. I will have to get off the freeway or the road. I am on trying to track off a couple of times for 5 to 10 minutes Until it stops doing it. It does it on average once to Twice a day. Was told could be brake calipers hoses, speed sensors sending the wrong information to the ABS system. It is very dangerous to drive the truck on the freeway doing 75 miles an hour!
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.
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.
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.
Im getting a service trailer brake system soon message on dash.
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.
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.
“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.
SERVICE TRAILER BRAKE SYSTEM - warning
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The 2018 GMC Sierra 1500 has 10 ELECTRICAL SYSTEM,SERVICE BRAKES complaints on file. Review the timeline above for detailed owner experiences.