NHTSA Complaint #11715791 — 2023 GMC SIERRA 1500

On or about Tuesday, February 3, 2026 at 12:20 CST, at the Chevrolet Dealership in Libertyville, IL; I presented my 2023 GMC Sierra to “Manny” at said dealership due to the vehicle INSTRUCTING ME TO DO SO because of DTC codes displayed indicating a failed DEF tank. I was told a technician would be able to diagnose the vehicle that afternoon. MakeModelYearVIN GMCSierra2023 [XXX] Day 1: came and went with no contact from the service department as promised. Day 2: Wednesday, February 4 came with – again – no follow-up from the dealer. When I CALLED I was told there were “no notes in the service order” and “the tech has gone home.” Day 3: Thursday morning “Manny” called to tell me nothing was done and nothing could be done. I was told to “call GM” and complain about my problem. This is how GM treats its customers. This is how GM treats its REPEAT customers. This is how GM treats its customers who BUY THEIR EXTENDED WARRANTIES. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)