2021 GMC SIERRA 1500 Complaints

Shift to park dings continuously and vehicle won’t turn off draining battery leaving doors unlocked. Don’t want to force into park and break anything more.

2021 GMC Sierra AT4, VIN [XXX] , NHTSA Campaign 25V-274, GM Case XXX. Brake pad monitor failed at 128,923 miles -- 24 miles after leaving Penske Chevrolet (released at 128,899, RO XXX, 04/17/2026). Brakes became spongy immediately following service. Monitor disabled entirely to stop recurring red Service System alert. Root cause is a burnt fuse block ground fault confirmed in writing by two GM-authorized dealers. Ray Skillman (RO XXX, 06/05/2025) documented the fault then deleted Labor Operation 14BUZ ENGINE ELECTRICAL from the recall repair work order. Penske documented verbatim: "all of these other faults share this same ground circuit." The recall repair at Ray Skillman used a remanufactured short block instead of a complete engine per N252494002. The original seized-engine oil pan has never been replaced across three dealerships and 128,000 miles. GM's own Part 573 filing states this defect "increases the risk of a crash." I drove 300 miles on an interstate on 04/22/2026 with active brake warning and no loaner because GM Executive Resolution refused to authorize one. Three GM dealers have inspected this vehicle. GM Executive Resolution Team [XXX] ) has not returned calls or emails and has not confirmed in writing this vehicle is safe to operate. OnStar issued a Critical Alert for P0617 on 04/15/2026. Zero brake faults existed in the 13 months prior to the Penske visit. This is a direct continuation of unresolved electrical damage from a botched federal safety recall repair at 384 days and counting. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Engine has a terrible shake, and I was informed by a mechanic that it has a misfire and no compression in piston number seven

Right after i bought the car I had a very bad misfire on cylinder 1, the car would shake at idle. Took to dealership and they said they replaced all the spark plugs and replaced cylinder 1 coil. about a week later the misfire and shaking started again but this time it would come and go. the check engine light would be on then it would go away for a bit and then come back on over and over again. The only thing that seemed to work is if i disabled the stop and go start system and put the car in L9 to disable the AFM. This seems to work and I have since bought a disabler for these systems. However, there is still a vibration at idle and i feel that its a temporary fix to a bigger issue. This is my daily driver and constantly have my children in the car and just want the car to be safe for everyone. The transmission downshifts rough and at times seems to slip/lock up while driving. I haven't brought it to the dealership for this as of yet.

I have the same model and year for GMC as bulletin 25NA-185, Engine Coolant Control Valve Failures on 3.0L Duramax (Dec 4, 2025), and am experiencing the same exact issue. Apparently my VIN is not included and I can't get an answer from GMC or the local dealer why it's not covered or how to have it reviewed to be added.

Coolant control valve has failed and caused the check engine light to occur is available for inspection. Could cause the car to overheat and cause harm to myself or others Yes has been confirmed by dealer No GM has a special coverage out for the specific vehicle and model years for this vehicle, but are stating that my vehicle does not pertain to that coverage.

Coolant control valve not working correctly exhaust fan on high all the time but is never overheating this has been going on for a week it shows there is a 150000 mile warranty on it but not for mine

The contact owns a 2021 GMC Sierra LD Crew. The contact stated that while driving on the highway at an undisclosed speed, the vehicle's bedrail attachment fully detached from the vehicle. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was unavailable.

Engine coolant control valve needed to be replaced. Special coverage (N252508341) was issued out by GM to fix this problem on 2021 GMC Sierra 1500 vehicles.

Driving normal traffic . Started hearing ticking . Check engine light flashing ,service esc and braking system light up. Parking not loud ticking from engine bay