Haven't posted here in a while. Sorry about that. I need some extra brainpower to help debug / troubleshoot my phone talking to my car. This one's a real head-scratcher.

Up to this morning, everything worked just fine. 2017 VW GTI, AA Wireless (v1), running 3.5 firmware, Pixel 9 Pro phone running the latest Android 15 and Android Auto version 13.4.645054-release. I drove to see a friend for lunch, using all of the above and it all worked properly. Got back in the car (*), and then total haywire.

Blank screen in the car, occasionally popping up "Reading USB" but making no progress. On the phone, "Android Auto is searching for the car".

So I tried a bunch of troubleshooting. Plugged the phone directly into the USB for the car. Didn't work! Discovered that USB was in charge-only mode so switched it to allow for file transfer & Android Auto. Still didn't work! Tried using Bluetooth. And that's where things get weird.

Phone screen: "Problem connecting. Turn device off & back on"

Car screen: (After selecting my phone on the Bluetooth menu) "Pixel 9 / Unable to connect to mobile device. The device AA Wireless is already connected through Android Auto."

I tried all the remaining obvious things after that. I told the car to forget the phone. I told the phone to forget the car. I disconnected the AA Wireless box. I power cycled the phone and the car, multiple times. I redid the Bluetooth pairing. I did an upgrade from the 3.5 firmware to the newer 4.5 firmware. I tried the USB cable again. Nothing worked.

So, something is really messed up here. I'm particularly unsure how to interpret the message in the car's screen, refusing to connect to my phone. Somehow, my car has associated my phone's Bluetooth with the AA Wireless device, even though I had it completely disconnected at that time. Like it refuses to talk to my phone any other way. This issue persists even after powering the car and phone, both down and back up again.

I'm usually pretty good at this sort of troubleshooting, but this time I'm stumped. I even pulled the logcat from the phone, but I don't really know what I'm looking for, and there's nothing obvious jumping out at me.

(*) This is a stretch, but here's an additional detail that might matter. I took my car to a carwash. Everything was working correctly while I was waiting in line. After it came time to hand my keys to the staff, I turned the stereo off but the car was still on while they were working on it. I went inside, which means that my phone and my car were presumably in and out of radio range. After this, the haywire behavior began. So, it's possible that something about this situation triggered the bad state of affairs.