2021 CHEVROLET SILVERADO 2500 Complaints

first issue was around April-May 2025 when my engine started knocking and burning fuel. Warning light came on and it went right in to the dealer where I have all my maintenance done. They determined that it due to (2) faulty fuel injectors and I had them replaced at that time. In December of 2025 my engine started doing the same thing as before with the knocking and burning fuel and reduced speeds when on the highway so again it went into the dealer. It has since been in there and first was told it was the fuel injector again. They priced out the one was bad and I asked them to replace the remaining 6 fuel injectors so I didn't have this issue again in the near future. They did and the vehicle had the same issues going on. During the next inspection it was determined that the engine needed new rocker arms. These were replaced but this also did not solve the problem and the vehicle would not pass the regeneration on the engine. During the next inspection it was determined that we needed to replace a cylinder and one of the valves. After this was complete they were still having issues and then I was told that the Piston was bad and there are (2) bad valves so I need an entire engine replacement. My truck only has 130,000 miles and has been in the shop for almost 2 months last year from engine issues and it has had all maintenance completed at he same dealership with Records.

The contact owns a 2021 Chevrolet Silverado 2500. The contact stated that the connector for the heater system was causing the vehicle to overheat, subsequently enabling the vehicle to go faster than 50 MPH. If the vehicle reaches 75 miles, it would immediately decrease in speed to 5 MPH. The vehicle was taken to a certified mechanic who diagnosed a P20C1 code, indicating reductant heater failure had occurred. The vehicle was not repaired. The contact called the dealer, who recommended calling the NHTSA Hotline to file a safety complaint. The manufacturer was informed of the failure they also referred the contact to the NHTSA Hotline to file a safety complaint. The failure mileage was approximately 68,000.

Unexpected roof rail airbag deployment without vehicle impact or accident. Front left and right side deploy - rear left and right side deploy spontaneously without notice.

Driving about 45 mph and unexpectedly both roof rail air bags deploy stoping vehicle on the road.

I own a 2021 Chevrolet Silverado 2500HD Duramax diesel with approximately 100,300 miles. The truck began displaying a “Service Emissions System” warning and a countdown message that in a certain number of miles the vehicle will be limited in speed (for example to 65 mph). GM’s own Duramax diesel owner’s supplement explains that when a “Service Emission System” message appears it is accompanied by a distance-until-speed-limit countdown and that the truck will progressively limit speed first to about 65 mph and then to about 55 mph if the condition is not corrected, telling the owner to see the dealer. This creates a safety risk because the derate can occur while driving on highways or rural roads, where an unexpected limit on maximum speed can interfere with merging, passing, and keeping up with traffic. This is our only vehicle, and we must use it for important medical appointments, including cardiology and surgery-related visits. The condition started only about 300 miles beyond GM’s 5-year / 100,000-mile powertrain warranty. I opened a case with Chevrolet / GM Corporate (Service Request No. XXX) and took the truck to Sons Chevrolet in Columbus, Georgia on November 17, 2025 for this issue and a rear wheel lockup recall. The dealer kept the truck from about 9:00 a.m. to 3:00 p.m. and indicated they might need to keep it for at least two more days, but I was not given a clear written explanation of the diagnostic trouble codes or a firm repair plan. Because GM’s own manuals describe this “Service Emission System” message together with speed-limit countdowns, and because the vehicle can actively limit speed on the road if the fault is not resolved, I am concerned this represents a broader emissions/derate defect on late-model Silverado HD Duramax trucks. I request that NHTSA review similar complaints and consider whether further investigation or a safety recall is warranted. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Took truck to dealer with concern of higher than normal braking force needed. Couldn’t verify concern. Looked today under the steering column and the brake booster is leaking fluid inside the cabin of the truck when the brake pedal goes through the firewall. There was Almost no brake fluid inside the reservoir causing the brakes to fail with no warning. Looked at similar trucks and all have brake fluid leaking from the same location. With as little as 10,000 miles. Mine has 22,000 miles and it’s failed requiring complet replacement of the brake booster. Taking to the dealership to replace the complete brake booster assembly when part is available. This is a 21 Chevy 2500 truck that pulls up to 18,000 pounds. higher than normal braking application needed, can be deadly or lead to complete brake failure whether loaded towing a trailer at a weigh of 25,000lbs or even the 7,000 pounds empty the truck weighs would reasonably result in the loss of someone’s life. Only thing that drew me to this concern was a harder application of the brake pedal and noticing brake fluid under the dashboard. Would gladly allow anyone to inspect my truck.

The contact owns a 2021 Chevrolet Silverado 2500. The contact stated that while slowing down and coming to a stop, the accelerator pedal was depressed while in drive; however, the vehicle started to roll backwards. The contact depressed the brake pedal to prevent the vehicle from rolling backwards, and the RPM became elevated to 5,000 RPM. The contact immediately turned off the vehicle to prevent the RPM from continuing to increase. The vehicle was shifted to park, restarted, and then shifted to drive(D) and the brakes released. While releasing the brake pedal, the failure reoccurred. The vehicle was immediately turned off and towed to the residence. The dealer was informed of the failure of the clutch pack, which was welded together from friction. The dealer scheduled an appointment; however, the vehicle was not diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 100,000.

We believe that it is the park sensor in the column . When you place the truck into park, the screen displays the words shift to park period and the dinger.Inside the truck continues to ding for a long time, even with opening and closing the door ... The truck is actually in park, so it does not move.But the display says it's not.And apparently it is not registering because it keeps dinging

Unable to remove key from ignition for a period of time ie. 30 sec. to a minute or more. After driving the vehicle for a either a long or short period of time and you park it, you can't turn the ignition lock all the way off.

In December of 2024 Safety Recall N2424440-01 was applied. On the morning of Saturday August 23, 2025 while driving on a two (2) lane highway with the cruise control set to 60 MPH the vehicle “shuttered” then the shifted into a lower gear locking the rear wheels bringing the vehicle to an almost complete stop in very short distance. I was able to pull off the road out of traffic. Since it was a light traffic morning, no one else was close limiting the risk to me. Had there been anyone behind me they would have been caught off guard by the sudden stop with no signal of brake lights showing. The vehicle is in “limp mode” and will not exceed 35 or 40 MPH. The vehicle will shift in to park and neutral. It will not move in reverse forward. The vehicle has been transported to the nearest Chevrolet dealership for diagnostics and service.