ELECTRICAL SYSTEM,SERVICE BRAKES07/16/2026
"The integrated trailer brake system abruptly fails while towing heavy loads, completely disabling trailer break stopping power and creating an imminent threat of highway crash and serious bodily injury." The sound system inherently stops working and will not produce sound from any device in the truck weather that be Hazards, Blinkers, Radio including AM,FM, Sirus Radio, Bluetooth or Car play as well as OnStar. The truck has been taken to a certified GMC dealer 4 times for these exact issues with also being provided the service bulletin information #N232414840 dated July 16, 2025 stating that the 2024 gmc 2500/3500 HD trucks requiring a new Trailer Break Control Module. This issue has been on going from September 2025 and still an issue as July 16, 2026 and still in the Shop today with a call back stating ready for pick up with the same module but dealer stated re flashed module. ( this is the 3rd reflash )
SERVICE BRAKES, HYDRAULIC07/09/2026
The contact owns a 2024 GMC Sierra 3500. The contact stated that while driving at an undisclosed speed, the front and rear brake caliper hoses collapsed. The failure caused a complete loss of braking ability. No warning lights illuminated. The vehicle was taken to a dealer where it was diagnosed that a brake hose failure caused the brake caliper hoses to collapse, impacting the brake caliper pistons. The manufacturer was made aware of the failure. The failure mileage was approximately 58,000.
FUEL/PROPULSION SYSTEM05/18/2026
Transmission valve body failure contestant with Recall # N242454440. Dealer diagnosed valve body failure and corrective action of Valve body rebuild. I would like 2024 models to be included with this recall for proper repair per Special Coverage # N242454441.
STEERING,WHEELS05/04/2026
The control arm bearing appears to have failed without warning causing loss of steering control. This occurred at low speed on a street in [XXX] last night near a gas station, so the driver was able to drive to a safe location easily without risk to life. Had the failure happened at speed a possibly fatal collision would have been likely. The vehicle has been used for the past 8 months to drive to work and has not been subject to any stress. It has not been modified. The tow truck driver said he has seen a number of other control arm failures recently, not necessarily in the same vehicle type. It may be due to bad pot holes this year in [XXX] , they are bigger and deeper than normal. This information is based on assessment by tow truck driver last night. Vehicle is at Jim Shorkey in Murrysville for repairs INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
FUEL/PROPULSION SYSTEM04/03/2026
The service department has identified "gasoline contamination" as the cause of a fuel system failure; however, this diagnosis is directly contradicted by both the shop’s internal test results and independent laboratory analysis.the shop performed an API Gravity test and a Styrofoam cup test.•API Gravity Result (35): According to GM Service Information (GMSi), the standard API range for #2 diesel is 30–39. result of 35 is a textbook "pass" for clean diesel. Gasoline contamination would typically spike this number into the 50s.GMSi protocol indicates that gasoline-contaminated diesel will melt a cup within 30 minutes.results only provided a "softened bottom," which is an inconclusive result per GMSi standards.Sinclair Refinery lab confirms the fuel sample taken from my vehicle is within 100% of factory specifications for diesel, with zero gasoline or DEF detected.Violation of GM Service Protocols even assuming the shop’s diagnosis of contamination was correct, the repair performed deviates dangerously from GMSi requirementsFor a 2024 L5P Duramax that has been cranked with contaminated fuel, GMSi (e.g., Bulletin 16-NA-376) mandates the replacement of the entire high-pressure fuel system, including the pump, both fuel rails, and all eight fuel injectors. shop replaced only the pump and cleaned the lines. This "partial repair" is not a GM-approved recovery procedure for contamination. Reusing potentially contaminated injectors and rails is the primary cause of catastrophic repeat failures.This clearly falls under warranty work and I should not had been charged for this repair. The dealership refusing to acknowledge my concerns and evidence is not only dangerous to the safety of myself and passengers, but raises concern for my vehicles future maintenance status, both inside and out of warranty. This shows a deceptive business practice and complete lack of accountability, compassion and moral understanding for the customer.I am owed a full refund and a warranty claim open
ENGINE AND ENGINE COOLING,FUEL SYSTEM, DIESEL03/05/2026
The contact owns a 2024 GMC Sierra 3500HD. The contact stated that while driving at various speeds, there would be a diesel odor coming into the cabin of the vehicle. The failure had become more persistent, causing black smoke to enter the cabin of the vehicle. The failure caused the contact and other vehicle passengers to have headaches, nausea, and dizziness. While driving approximately 65 MPH, the contact began speaking to their daughter, sitting in the front passenger seat, and noticed her not responding. When looking over, the contact noticed her daughter's head was lowered. The contact immediately pulled over to the side of the road, where she pulled her daughter out of the vehicle and called an ambulance. A fire truck was also dispatched in order to drive the vehicle to the fire department, where they tested the vehicle; however, they were unable to duplicate the failure. The contact's daughter was taken to the hospital, where it was determined that she had suffered from carbon dioxide poisoning. The vehicle was taken to the dealer, who diagnosed that the Diesel Particulate Filter (DPF) was clogged, and that the Exhaust Manifold and Turbo Inlet were both fractured, causing a blockage in the Engine Bank. It was determined that all the avenues through which air and carbon should have been exiting the vehicle had failed and were causing everything to come into the cabin of the vehicle instead. The vehicle was scheduled for repair; however, only the exhaust manifold could be repaired, while the other parts, such as the DPF and hose, were on national backorder and awaiting retrieval. The manufacturer was informed of the failure, and a case was opened. The contact stated the manufacturer had been avoiding acknowledging that black smoke had been entering the vehicle's cabin and had yet to resolve that issue. The failure mileage was approximately 20,000.
POWER TRAIN,ELECTRICAL SYSTEM,ENGINE02/17/2026
This 2024 GMC Sierra Heavy Duty has experienced a continuous pattern of major mechanical and electrical failures since early ownership. The vehicle required a complete engine replacement under warranty at approximately 43,626 miles. Since that time, the vehicle has continued to experience repeated injector failures, control module faults, communication errors, and voltage-related system issues. Current diagnostic codes indicate multiple simultaneous failures including ignition relay feedback circuits, control module power faults, gateway communication loss, brake system communication faults, and battery voltage circuit errors. The dealership has diagnosed a power distribution / fuse block failure at approximately 79,000 miles. These electrical failures affect multiple vehicle systems and raise concerns regarding reliability and potential safety risks due to loss of communication between control modules and possible braking system interaction. The vehicle has been in the dealership numerous times for repairs including engine replacement, injector replacement, control module reprogramming, and electrical diagnostics. I am submitting this complaint due to concern over a potential systemic electrical defect and ongoing reliability issues.
POWER TRAIN01/31/2026
Rear wheel lockup event in traffic while towing 24000lb 5th wheel on freeway. Vehicle was limped to a dealer, diagnosed as a transmission valve body failure. Repair took over 1 month stranding us over 1500 from home while on a trip.
ENGINE11/18/2025
The engine oil drained into the radiator from a flaw in there design in which outrageously high labor cost for the owner of the vehicle they put a rubber house in the radiator in which leaked without any warning indicating that there was a problem with the oil nor the radiator coolant system. repairs are in the thousand and I as a consumer should have this matter resolved at no cost due to bad design cost they should have made a oil cooler with its own separation compartment like the transmission cooler because they are replaceing everything else what about the engine itself thats still going to be contaminated like all the replacement part, seal hoses,and radiator, coolant, and thermostat. How can just parts be contaminated but not the engine? They are just replacing things that costs alot. This is a drive train issue, there were no oil in the engine.
SERVICE BRAKES09/29/2025
My truck is experiencing the Brake Controller failures as documented in GM Bulletin N232414840 - Customer Satisfaction Program Intermittent Loss of Trailer Brakes. This problem has occurred several times over the past year. I thought it was the wiring on my trailer - so I checked and found no problems (plus it works properly on other tow vehicles). Additionally, the problem resets and works properly after turning the truck off and back on (resets the system). It then works properly until it unexpectedly disconnects again. I thought the problem was unique to my vehicle until I got online and discovered that this is a known issue for others as well (2024 GM HD trucks). I contacted my GM dealer (and GM's customer satisfaction center as noted in the bulletin) and they informed me that my truck is not covered under this recall (not one of the covered VINs). I told them that I'm having this issue and they told me to report the problem to the NHTSA. Needless to say, GM has not included all the applicable vehicles in their recall (like mine) and I need the issue corrected before it causes a serious accident.
STRUCTURE,UNKNOWN OR OTHER09/15/2025
Front wheel well liners keep falling out of place like they are melting. happens when towing and engine gets hotter than normal. Trailer is well below limit for vehicle. Liners fall onto the tire while in motion. This is the 4th time this issue has happened to my vehicle. Dealer replaces them and says it happens all the time.
SERVICE BRAKES08/12/2025
This is my 4th GM 3500 dully and the first time with this kind of problem. I took my truck in for inspection and it came back with a clean bill of health about 25,000 miles on the 2024. When I got it back I noticed a vibration when breaking. I took the truck back in to find it had bluing on the rotors and the break pads have holes in them. I was told this came from over heating. I looked up info to see if this was a common problem and found the in 2022 GM changed the material to help with noise problems and this material had been know of premature break problems. I called GM customer service and they told me to work with the dealership, the dealership called the district manager and all parties have decided to ignore the issue. I also have 2 of these truck driven by 2 different people with the same problem at the same millage. I will make a 2nd report for the 2nd truck.
Showing 12 of 42 complaints.