*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Electrical system
GM Duramax L5P diesel engine electrical connector for #4 fuel injector. This failure caused the Diesel exhaust brake, which controls downhill speed, to disengage, extreme shaking of the vehicle, emissions system warning and speed limiting. This occurred while descending a steep grade while towing a 34 feet long, 10,000 pound trailer. This is a known issue with this diesel engine and documented in GM Technical Service Bulletin 23-NA-027. Inspection and repair at a GM dealership confirmed a known issue with the #4 injector pigtail connector caused by improper wire routing and interference wit the Sound Shield and Valve Cover Heat Shield This was a sudden failure of the #4 pigtail connector…
May 2, 2026Visibility/wiper
The component that failed is the rear glass. Yes, it is available for inspection. The rear glass defogger stopped working and melted the tabs off of the glass and burned the tabs cover. The problem has been confirmed by the dealership and i was advised there is already a recall for this but apparently my vin does not fall under the recall.
Feb 3, 2025Electrical system
Service Trailer Brake System Warning From time to time, this warning goes off in the vehicle and when it does, it does it constantly. When the warning is dismissed, it does it again seconds later. If it is not dismissed, it does it again seconds later. It is a persistent three ding double chiming that is not only constant, the vehicle is doing it without a trailer connected to it. The GM dealerships we have been to regarding this issue do not know how to fix it since the warning is as intermittent as it is persistent. Once one of the dealerships was finally able to observe the warning themselves, we were told because it does not cause the check engine light to come on, they are not given a…
Aug 31, 2022Fuel system, diesel
The contact owns a 2018 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The vehicle was towed to the dealer, where it was determined that the fuel pump control module needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 48,000.
Sep 26, 2024 · 48,000 milesFuel/propulsion system
Metal in the fuel filter and throughout the fuel system, 38 codes on the computer just in 2 weeks after a full service again at the dealer. All service has been preformed at A GMC Dealer since truck was serviced. 1. P026D - Fuel injection Quantity âAâ Higher then expected 2. P06CC - cylinder 8 incorrect 3. P133F - cylinder 8 glow plug offset exceeding learning limits None stop this is happening since [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Nov 6, 2023Fuel/propulsion system
Constant issues with glow plug failures, fuel rail failure, fuel pressure failure. Truck has been in the Gmc service regarding these issues constantly for the last year with a total of five repairs and replacement of glow plugs with releaning learning new plugs and now the 6th return to the shop theyâre tearing down the fuel system. Malfunction and engine light consistently come on with the same occurring problems generating from the fuel system and glow plugs. Fuel mileage is absolutely terrible and lose of power hazardous to safety!!! Gmc has issued an extended warranty for 15 years and 150,000 miles, but cant and hasnât found a repair for vehicle and just replaces the glow plugs just…
Aug 1, 2022Wheels
driving at 70mph, thread from tire blew.. That was in July, I went and purchased another tire from Bob King GMC Wilmington, NC. The first tire that blew was now discontinued so I purchased another Good Year . On Friday I noticed that another tire on my truck had a bubble along the threads again. It was also getting ready to blow like the first tire. I went to the dealer and they told me the tire I purchased (Good Year) was also discontinued... Please look into this matter.. They have faulty tires and this matter could have turned out with a death.. It isn't the dealers fault it is Good Year .... I have also read on line this isn't the first time people are complaining about the threads…
Jul 23, 2023Electrical system
While braking ( after being on the highway) all dash gauges turn black, radio shuts off, AC shuts off. Service Stabilitrak light comes on when dash flashes back on. While driving AC turns off, Radio turns off same stabilitrak warning flashes, speedometer turns off. Power steer control went out while trying to turn. Truck put itself in 4 wheel drive when I turned on the trailer assist. Parking assist periodically turns itself off.
Aug 20, 2023
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.