Subject: Urgent Safety Concern a“ Widespread Failure and Nationwide Backorder of OnStar Module (GM Part No. 86803964) Dear NHTSA, I am writing to formally raise a serious concern regarding a widespread and well-documented failure of the OnStar module (GM Part No. 86803964) in 2023 GMC Sierra vehicles and potentially other GM models. I own a 2023 GMC Sierra equipped with this module, which has failed, rendering my vehicleas entire instrument cluster completely inoperative. All screens, including the digital gauges and essential driver information displays, are blacked out, leaving the vehicle in an unsafe and non-drivable condition. After contacting numerous GM dealerships across the country, I have discovered that this part is on national backorder, with over 4,000 units reportedly pending. I have also learned that the part number has been superseded multiple times, suggesting an ongoing and unresolved issue. To make matters worse, Specmo is reported to be the sole refurbisher and distributor of replacement modules, further limiting availability and delaying resolution. This issue directly affects vehicle operability and driver safety. The inability to access critical information such as speed, fuel level, warning indicators, and system diagnostics significantly increases the risk of accidents and vehicle malfunctions. Given the scale of this issue and its impact on public safety, I urge General Motors, relevant regulatory bodies, and consumer safety agencies to investigate this matter thoroughly. A recall, expedited solution, or broader communication to affected customers appears necessary at this stage.