Technical Requirements
In general, the Echo Auto is compatible with all car radios that have a Bluetooth connection. This also applies to the smartphone. Without a smartphone with an active mobile Internet connection, the Echo Auto cannot function because – unlike other Alexa products – it does not have its own WLAN connection.
The smartphone used must have at least Android 6.0 or iOS version 12. The hardware uses a Mediatek MT7697 and a Dual DSP from Intel with interference engine.
The protocols of Apple CarPlay and Android Auto are supported. Bluetooth connectivity is provided via the Audio/Video Remote Control Profile, the Advanced Audio Distribution Profile and the Hands-Free Profile. For Android the Serial Port Profile and for iOS the iPod Accessory Protocol is also used.
Some smartphones are not supported. These include, but are not limited to: The Samsung Galaxy S8 as well as the S10 and S10+, all Generation 1, 3, 4 and 5 iPhones, Google Nexus 4 and 6 and the Honor 4C, 7C, 7X and 8X. A complete list can be found on the official Amazon website. There you can also find a list of incompatible vehicles, with a special focus on the Bluetooth connection. With an AUX connection, the Echo Auto can usually still be connected to the car radio.
The Echo Auto has no display and therefore occasionally uses the smartphone’s display to show information or confirm commands. Therefore, it is necessary to have a suitable cradle for this purpose, which allows it to be operated while driving. A cradle for the smartphone is not included and should be mounted in advance of the actual setup.
https://diysmarthomeplanet.com/echo-auto-setup/#Troubleshooting_Troubleshooting