Check Hardware Connectivity
Changing the USB cable, you connect your mobile to the car and run android auto. Usually, USB cables more than 2 meters long, in poor condition or without the official USB logo, are not compatible with Android Auto.
Don’t forget that the USB cable you use must be able to transmit data and also remember not to use extensions USB cables. In short, use only a high-quality USB cable.
Android Auto Compatible Phones.
Android Auto app works with Android 5.0 and later. However, Google recommends us to use Android 6.0, as a minimum requirement, to enjoy the android auto apk without problems. Therefore, install Android Auto apps on a mobile phone that has Android 6.0 or higher to try to solve the problem android auto not connecting.
Also, make all the system and apps updates that you have pending on your mobile and from the Play Store. Update all the multimedia apps related to Android Auto. Finally, we also advise you to restart your smartphone to try to solve the android auto suddenly not working problem in this way.