Second complete powertrain failure on March 14, 2026 at 13,993 miles, nine days after first repair (complete transmission replacement for bone-dry sealed transmission). Symptoms: sudden loss of power on highway (unable to exceed 20 mph with accelerator fully depressed), hollow sound, noise described as "like a rock tumbling around inside." OnStar diagnostics returned "No Error Code Found" twice (11:14 AM and 11:17 AM) during active failure. Dealer (Loveland Buick GMC) diagnosed "battery issue" but provided indefinite loaner with no return date. Symptoms are consistent with engine bearing or connecting rod failure matching Cook et al. v. General Motors (Case No. 1:26-cv-00229, D. Del., filed March 4, 2026) covering 1.2L/1.3L turbo engines in the Buick Encore platform. Complaint alleges GM knew about defect "since 2022, if not earlier" and instructed dealers to tell consumers vehicles are "operating normally." First failure involved sealed transmission running with zero fluid. Skipped oil change after transmission repair (documented in GM Executive Resolution emails) may have allowed metal contamination to damage engine components. Requesting investigation into whether dealer's "battery" diagnosis was accurate or whether actual diagnostic codes indicate engine failure consistent with Cook v. GM class pattern.

Source: NHTSA complaint ODI #11728488 · view all complaints for this vehicle at nhtsa.gov

The contact owned a 2025 Buick Encore GX. The contact stated that while driving at an undisclosed speed, the GPS failed to operate properly. Additionally, the air conditioning system was inoperable. The contact stated that while driving in the heat, the contact to briefly became unconscious. Due to the failure, OnStar was contacted to providing GPS assistance. After arriving to the destination, the navigation system started operating as designed. The dealer was contacted and diagnosed the vehicle with engine under-boost failure, loss in communication with the telematics communication interface control module, an open ethernet bus, an auxiliary heater command low voltage, lost communication with the inflatable restraint sensing and diagnostic module, and loss of communication with the direction camera control module. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 20,000.

Source: NHTSA complaint ODI #11751200 · view all complaints for this vehicle at nhtsa.gov

While driving my 2025 Buick Encore GX Avenir, I experienced a sudden, catastrophic electronic and mechanical failure. Without warning, the brake pedal became extremely stiff, requiring massive physical effort to slow the vehicle down. Simultaneously, the dashboard displayed warning lights indicating that both the StabiliTrak system and the Power Steering system were disabled, causing a sudden loss of steering assist.The vehicle was towed via Buick Roadside Assistance to Ewing Buick in [XXX]. This simultaneous failure of braking, steering, and stability control represents an extreme safety hazard. The vehicle is currently at Ewing Buick, who is the dealership that sold me the vehicle in October 2024. The failure was accompanied by the warning lights on the dashboard at the same time of brake failure. I am a liver transplant and I bought this car so that I would have a safe vehicle I am now concerned because of possible blunt trauma to my abdomen if I have an accident. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Source: NHTSA complaint ODI #11759400 · view all complaints for this vehicle at nhtsa.gov

I had just drove the car off the lot. On my way home there is this violent grip of the steering wheel pulling me into oncoming traffic. Then again to the right towards a telephone pole. During another casual drive, there was a loud clunk and another violent grip of the steering wheel to the left towards the double yellow line, my son was driving the car at the time. This has happened numerous times. I explained to the dealer that lane assist is suppose to keep you on the road not pull you off the road. There were no lights showing on the dash. Unfortunately this happens randomly so it did not happen when the car went in for service repair at Turner Buick. Turner Buick did not find the cause and did no repairs. If I leave lane assist turned off my car is fine however it is a brand new and its a feature I am not able to use. My car is available for inspection upon request. This is my first Buick and I am disappointed.

Source: NHTSA complaint ODI #11660274 · view all complaints for this vehicle at nhtsa.gov

The vehicle has a safety-related defect involving the safety restraint system. A warning message/light appears indicating a malfunction affecting occupant protection. This defect raises concerns regarding proper airbag and restraint operation in the event of a crash. I presented the vehicle for warranty service, but the manufacturer refused to diagnose or repair the safety defect solely because the vehicle was not currently registered. The vehicle is otherwise under warranty. No accident has occurred yet, but continued operation with this defect poses an unreasonable risk to the driver and passengers. The defect has been observed multiple times and remains unresolved. I am reporting this issue to NHTSA to prevent potential injury or death before an accident occurs.

Source: NHTSA complaint ODI #11707190 · view all complaints for this vehicle at nhtsa.gov

Component: Parking Assist / Driver Assistance Sensors / Object Detection Incident Description: While operating my Buick Encore GX, I executed a controlled, low-speed right turn and struck a stationary structural column within the vehicle’s path. The column was a fixed, solid object located in close proximity to the vehicle—precisely within the range the vehicle’s parking assist and object detection systems are intended to detect. No audible or visual warning was provided at any time prior to impact. According to the owner’s handbook, these systems are designed to detect nearby obstacles and provide alerts during low-speed maneuvers, including turning and parking. The conditions of this incident fall directly within those operating parameters. The system’s failure to detect and warn of a clearly present obstacle constitutes a safety defect. Safety Risk: The driver assistance system failed to perform as represented, creating a heightened risk of collisions with stationary objects in low-speed maneuvers. Drivers relying on these systems cannot reasonably expect alerts to avoid collisions in confined spaces such as parking structures or tight turns.

Source: NHTSA complaint ODI #11726256 · view all complaints for this vehicle at nhtsa.gov