NHTSA Complaint #11664215 — 2023 GMC SIERRA 3500

Formal Complaint Against General Motors and Dealership – Ongoing Warranty Issue and Vehicle Inoperability To Whom It May Concern, I am writing to formally escalate a serious and unresolved issue regarding my vehicle, and the lack of meaningful action taken by both General Motors (GM) and an authorized dealership. My case is not isolated, it mirrors the experience of thousands of other GM customers facing the same known mechanical defect, as widely documented in online forums and communities. On [XXX], I purchased a used 2023 GMC Sierra 3500 Denali with approximately 25,000 miles from a dealership. The vehicle included the original factory warranty, and I also purchased an extended warranty for additional coverage. On [XXX], at approximately 26,000 miles, the truck unexpectedly entered limp mode and the check engine light came on while I was driving with my children. Please note—this truck is equipped with the Allison Transmission, which is marketed as one of the most reliable transmissions available. I immediately took the vehicle to Blade Chevrolet in Mount Vernon WA, the nearest dealership, where it remained for nearly a week before a diagnostic was completed. I was informed by the lead mechanic, Jason Visten, that the issue was a failed valve body solenoid #1—a component he clearly identified as a known and widespread issue within GM’s system. Mr. Visten further stated that GM has not been responsive to the dealership's requests for this part, which is currently on national backorder with no estimated timeline for availability. I was even told this specific part is being built for new vehicle production and are being prioritized over parts needed for warranty repairs, leaving my truck unusable and indefinitely sidelined for up to a year per Blade Chevrolet. I contacted GM Customer Service directly and received the same generic response. Also worth mentioning I almost got rear ended cause of limp mode activation and transmission locked up. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA