Some 2020-2021 Corsair/Aviator/Navigator and 2021 Nautilus/Mach-E customers may be unable to activate Phone-as-a-key, have intermittent Phone-as-a-key connectivity, missing Phone-as-a-key button in the App, receiving Pairing Failed, Key Download Error or Connection Trouble message during Phone-as-a-key setup, Bluetooth Disconnected, Unable To Start, Backup Code Needed And/or Key Not Detected. Prior to performing any RFA diagnostics, verify the customer's phone app is at the latest version, the phone app is authorized to the vehicle and Location Service is enabled in customer's phone to allow for proper Phone-as-a-key operation. If a Phone-as-a-key concern remains, continue with normal RFA diagnosis. Refer to Workshop Manual (WSM), Section 419-01. Utilize the FordPass Guides or Lincoln Way Concierge teams as needed to understand Phone-as-a-key operation.