2020 GMC Sierra 1500 electrical problems

Filed Oct 7, 2026 · Electrical · 51,000 miles · MD

The contact owns a 2020 GMC Sierra 1500. The contact stated that the vehicle failed to start intermittently and needed to be jumpstarted. The vehicle was taken to the dealer, and it was determined that there was corrosion on the ground wire which caused the failure. The vehicle was not repaired because the vehicle was not included in Customer Satisfaction Program: N252515590 with the federal safety agency ID Number: 11027795 (Electrical System) for the ground wire replacement. The manufacturer was informed of the failure and confirmed that the vehicle was not covered. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 51,000.

Filed Sep 28, 2026 · Electrical, Engine · AK

6 months after owning it the lifters went bad got them Fixed then they immediately went bad again also bent rods then a day after getting that fixed again the oil pump went bad it was issue after issue

Filed Sep 15, 2026 · Electrical, Engine · MS

5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake manifold.

Filed Aug 24, 2026 · Electrical, Engine · TX

Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts with GM dealers repeatedly stating the issues were repaired and returning our vehicle to us. We began making the CEO and Executive team aware of the potentially deadly safety hazards including the fact that I, [XXX] am disabled and power wheelchair dependent requiring a truck that can carry my power wheelchair. We have sent numerous emails to Ms. [XXX] and the Executive team numerous times informing them in detail, each time, of all issues involved. We started communicating via phone and email with customer care to no avail. All attempts at repair finally ended in complete engine failure leaving us with an estimate to replace the engine of over $13,000. We have also, submitted a detailed complaint to the Attorney General’s Office and after review were given the Case # TCP - XXX. I will attach the Complaint and Addendum sent to the Attorney General along with two of the emails sent to Ms. [XXX] and her team informing her of all issues with the truck. They took no action to actually help us get this truck off of the road knowing it was having catastrophic engine and system failure and that it had to be driven to transport a disabled power wheel dependent with severe medical issues and the medically necessary power wheelchair. I am also attaching the earliest OnStar Diagnostic notice of Engine, Transmission and Emissions system issues from May of 2023. The issues have remained the same from the beginning only worsening though my husband has only driven the truck in town on slower less busy streets learning how to make adjustments such as pumping the brakes and starting and stopping the truck to keep it going. My carrier is installed and yet it is undrivable. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATIO

Filed Jun 8, 2026 · Electrical, Engine · MI

- the ground strap corroded and broke apart. Yes, I have the ground cable that failed, if needed for inspection. - yes!!! The truck's steering kept going in and out of manual steering and the engine reduced in speed allowed, and then the engine cut out on me completely - while I was in the middle of a busy road trying to turn onto a side street. Then the engine would not restart. - I had the truck towed on a flat bed to a gmc dealership nearby. They confirmed the issue was that the ground strap failed. They replaced the part at my cost, which fixed the issues. - yes, the dealership inspected and confirmed the issue was the corroded and broken ground strap. - yes, there were many warning messages that started to appear about 3-4 days prior to the complete failure of the electrical system. I started seeing a message about servicing the trailer brake system, and another about servicing the side detection system. Then a service power steering warning and to drive with care. The check engine light was off and on over that time. - I checked the wire connections iunder my vehicle to check for broken wires or corrosion. I did not find any. I then checked if a hard battery reset would work, but it did not. Lastly, I bought a new battery to replace the existing one, even though the existing battery had no issues even when tested under load. That resolved the issue for about 35 minutes that night and then the next morning. After that, the electrical system failed and the truck would not start. At that point I got towed in to the gmc dealership. I had to leave the truck for a weekend, and the dealership did not come up with a loaner, even though I requested one. I got the truck back on monday afternoon and everything was working fine since then. - over that weekend, I was amazed to find out about the bulletin gm released to cover only some trucks for the issue, but not others! My truck is still not covered, despite the obvious safety issues I experienced!!

Filed Jun 2, 2026 · Electrical · KS · fire

Fire started under passenger side front seat dashboard when rear defrost was turned on.

Filed May 23, 2026 · Electrical · MA

2020 GMC sierra 1500 infotainment system including navigation,OnStar and voice command, stoped working on Friday May 15th with no prior warning. These systems are integral for modern safe travel and severely affects the value and driver confidence in the vehicle. It seems to be running mechanically sound but, with some of the communications and information systems not working properly I am unsure how much of the info is incorrect like the clock (which can not be set manually). I have scheduled an appointment with the dealer for June 2nd the earliest date available.

Filed Apr 6, 2026 · Electrical · ID

Infotainment screen is flashing different colors and doesn’t work anymore.

Filed Mar 20, 2026 · Electrical, Transmission · NC

Truck broke down with a rear-wheel lockup and had the transmission replaced in June 2025. In December 2025 and February 2026, truck lost power two times and entered limp mode while on a major highway and major interstate. The problem was misdiagnosed in June 2025, diagnosed properly in December 2025, but not properly repaired, and diagnosed properly in February 2026. All three times the vehicle had this issue, two of the same exact DTCs were present. This is a safety defect, and I have lost all confidence that the vehicle is reliable enough and safe enough for myself and my family.

Filed Mar 16, 2026 · Electrical · 175,000 miles · MI

Odometer Fraud. The contact attempted to purchase a 2020 GMC Sierra 1500. The contact discovered a mileage discrepancy. The vehicle was a private sale. At the time of purchase, the mileage was 75,000. At the time of registration, the Carfax Report indicated that the mileage was 175,000.