Following this.
I have the same setup and same issue.
(Pixel 8a though)

I also have this issue on a pixel 8 pro. A previous update also stopped wired from working, only wireless works for me now. The audio broke after the most recent stable update. I also have the same permissions set.

I should have read the new version release post first haha! Looks like the temporary fix is granting AA microphone access. Will report back if it doesn't work for me.

Copying the post in the thread that helped me, by yere:

Android 15 QPR1 introduced a bug requiring the Microphone (record audio) permission for routing local audio too. It impacts Android Auto on both GrapheneOS and stock OS, but only users on GrapheneOS will notice it because the permissions aren't granted by default.

https://grapheneos.social/@GrapheneOS/113629803646184979

Our next release will have a fix for this issue to avoid the audio recording permission (Microphone) being needed.

If you need this feature and don't use the voice features for Android Auto, you can choose if you want to work around it by temporarily granting it this access.

https://grapheneos.social/@GrapheneOS/113629804204322533

Latest GOS on 8P, lost audio routing in AA as well. Gave AA app microphone access but to no avail. Still cannot get any audio to play through AA. Tried AntennaPod, Audiobook Voice. Moved from Work profile to Private, reinstalled AA. Seems like I am missing a workaround step somehow.

    When the issue began, I tried uninstalling and reinstalling AA on my pixel 7a. After reinstall, AA simply doesn't connect to my toyota head unit. The car keeps popping up with a warning saying the time on the device does not match. Anyone know about this?

    • de0u replied to this.

      Donated2562 The car keeps popping up with a warning saying the time on the device does not match. Anyone know about this?

      The exact text of the warning might be useful.

          de0u
          Certainly. The error reads as follows:

          "The time on your vehicle system does not match the time on your android phone. Please move your vehicle to a location where it can receive GPS signal so the clock is set automatically"

          It's worth noting that the clock has indeed been set automatically. Googling shows other people with this error both on GOS and stock Android, but I can't find a solution.

          • de0u replied to this.

              de0u
              I appreciate you taking a look for me. I did try the recommendations in that thread as well as several others. From what I've seen, this is a general connection/incompatibility/security error, but this only means that identifying the actual cause will be more difficult.

              • de0u replied to this.

                  Donated2562 I did try the recommendations in that thread as well as several others.

                  Based on what I read, I would probably try something like this:

                  1. Disable the Android Auto app in Settings
                  2. In settings, clear cache and storage for Android Auto
                  3. Uninstall Android Auto
                  4. Once Android Auto is uninstalled, tell the car to forget the phone and tell the phone to forget the Bluetooth pairing with the car
                  5. Make sure both car and phone have the correct time
                  6. Reinstall Android Auto (granting permissions etc.)
                  7. Try connecting Android Auto to car with a USB cable
                  8. Only then try Bluetooth/Wi-Fi

                  But I am not an Android Auto user; the suggestions are just my distillation of what I think I saw online.

                      de0u

                      Thank you, this is very actionable. I will try all of these once back in the car.
                      For clarity, it is the wire connection specifically that doesn't work. I can play audio over BT, but obviously, overusing wireless defeats the purpose of GOS.

                      Out of curiosity, what permissions do you grant AA? I only enable notifications and (since this thread) microphone.

                      • de0u replied to this.

                          de0u
                          Thank you for all your help. After everything, it turns out that the solution lurked in a settings menu in sandboxes google play services.
                          For anyone else reading this who also doesn't read the fine print, go to settings, apps, sandboxes google play services, android auto, and toggle on USB access permission and audio permission.

                          • de0u replied to this.
                              2 months later

                              • TThP

                                • Post #20

                                Using the latest version of GrapheneOS (20250205) I still facing the "no audio" issue. Any hints?
                                Note:

                                • wired connection permission: ON
                                • wireless connection permission: OFF
                                • Android-Auto microphone permission: OFF
                                  Test: I tried to have a Signal/Whatsapp message read out loud, clicking on the car display's "Read this message" does nothing

                                What else should I check?

                                  ThP Do you have a text to speech engine installed? If you do not like Google's Speech Recognition & Synthesis you can try e.g. eSpeak.

                                  • ThP replied to this.