NHTSA Complaint #11666340 — 2023 GMC SIERRA 1500

While driving vehicle I received a message on the dashboard, "Reduced acceleration, drive with caution" and then the check engine light came on. Took the vehicle to local Autozone to get code read and was told "P1028" was the error code. Schedule an appointment with local GMC dealership for diagnosis. After three days dealership told me that the technician has diagnosed my truck with faulty "Engine Coolant Control Valve". I was told the part is backordered with no ETA. Asked for a loaner vehicle while truck is waiting repair and was told there was nothing available. When asked about what I should do transportation, dealership told me I could come pick up the truck and drive it until part arrived but I would need to watch for further engine issues as the engine could overheat. How do you tell a customer to just continue driving a vehicle with a known issue. Additional fear is what if additional harm is caused and because I drove the vehicle with a known issue they won't cover the cost of repair? This all seems fishy and unfair as a consumer.