NHTSA Complaint #11673151 — 2024 GMC YUKON

I am filing a complaint regarding a potential safety defect in my 2024 GMC Yukon Denali (approx. 25,000 miles), which has been in the dealership’s service department for about 30 days due to a faulty valve body in the transmission system. There is currently no estimated date for repair completion due to a lack of available parts. This is the second time the vehicle has been in the shop for the same unresolved issue. Earlier in 2025, I brought the car in due to driveability concerns and error messages appearing on the dash, but the dealership dismissed it and claimed I had “turned the vehicle on wrong,” despite it having a push-button start. The problem persisted until June 2025, when they finally diagnosed the valve body failure. This issue directly affects drivability and vehicle safety, particularly during acceleration and gear shifting. I am concerned that General Motors is aware of widespread valve body and transmission failures in these vehicles, yet continues to produce and sell new units while failing to ensure parts are available to support timely repairs. It is unacceptable that a major safety-related transmission issue can sideline a relatively new vehicle for over a month with no resolution in sight. GM’s lack of urgency in addressing this defect suggests a disregard for consumer safety and reliability. I respectfully request that the NHTSA investigate this issue as a potential pattern of safety defects in GM’s full-size SUV transmission systems.