Phone audio no longer routing over Bluetooth in car for anything other than phone calls.

[Digsy]

Huawei P20 user here on Android 10.

I used to be able to access all the Google Assistant features on my phone by pressing the "voice" button on my car's steering wheel. This would mute the stereo and route all phone audio over the car's speakers. So I was able to read and dictate text messages, create new calendar entries, etc, etc. Basically anything I could do hands free on my phone I could also do via my car's hands free speakers / microphone.

However since about two months ago this has stopped working. Or rather, it now only works for calls. Pressing the voice button still works, but for anything other than calls the phone audio now only plays over the phone's speakers and the car does not mute the radio / media, so I cannot hear the phone which renders it useless (unless I manually mute the stereo).

At the moment I don't know it this has been caused by a phone software update, or a car software update, or what ever. Its also not easy to pin down when the problem started as even though it is useful and I miss it now it is gone, I never used to use this feature much. I discovered it by accident a few weeks before Christmas when someone sent me a text message while I was driving and I could not get it read to me over the car's speakers. All I know for certain is that it used to work but does not now.

Anyone else noticed anything similar? 

[hrym]

In a quiet moment, I did a bit more digging and found this.  It isn't specific about what problems it refers to or fixes, but there's a simple and non-destructive procedure (clearing the cache) that might be worth a try.

[Digsy]

I have tried that already but I think I may try it again while also deleting the car form my phone and the phone from my car at the same time.

Also, do you know if there is a way to completely reset Google Assistant back to default so it is like I am using it for the first time again?

[Evie]

Good idea @Digsy, give that a go and let us know how you get on!
In regards to your Google Assistant, I've had a search on Google and can't find an definitive answer as to whether it's possible to factory reset it. However, I did locate this Google Assistant forum which asked the same question and gave a few troubleshooting steps to try 👍 Hope this helps!

[Digsy · Accepted solution]

FIXED!! At least for now.

I followed Evie's link to the Google Assistant forum and did these two operations (I don't know which one actually fixed the issue).

Cleared the Google (G) app Cache. 

Open your phone's Settings app.

1. Tap Apps & notifications.
2. Tap the Google (G) app. If you don't see it, first tap See all apps or App info.
3. Tap Storage & cache: Clear cache

Uninstalled all updates to the Google app:

Open Google Play Store > search for Google (G) app > open app > Uninstall > OK > Update > wait for update to install > Restart phone (NB a restart was not necessary in my case)

This caused Google assistant to reset itself, although it seemed to retain some of my settings. 

After doing this, it worked in my car as previously. I then did the following additional step of disabling auto-updates to the Google app:

1. Open the Google Play Store app 
2. Tap Menu  > My apps and games.
3. Select Updates
4. Select Google from the apps list
5. Click the "three dots" menu (top right)
6. Un-check auto update.

Thanks so much everyone for your help! Hopefully this will carry on behaving from now on.

[hrym]

Glad to hear you're sorted.   I'm also interested to hear that you can apparently turn off auto-updating for individual apps - I'm pretty sure that this was previously only available globally.   When you get updates, Google will appear on the list (afaik), so make sure it doesn't get selected accidentally.

[Digsy]

Well... This worked just great until last week when my phone started telling me that in order to continue using some features of the Google app I *had to* update it. So I updated it and the issue with my car's hands free features came straight back. Luckily I was able to uninstall the updates again but now it seems I have to choose between limited functionality on my phone versus limited functionality in my car. Way to go, Google.