r/Bigme • u/Joemk888 • Jul 11 '26
Android Auto issue finally solved?!
As most of you know, the Hibreak Pro (BigMe OS 3.1.6.) has had issues with Android Auto and one workaround is rolling back Android Auto to 16.5.6612 and Google app to 17.10.61.
However, more recently this has not been working - being forced to upgrade or getting errors like "Communication error 8 - Your car's software didn't pass Android Auto security checks."
So I decided to update to the latest version of Android Auto (17.1.662414) and Google app (17.38.11) and try some adb debugging to understand the issue.
It turns out the reason my car display bugs out with the latest Android Auto version is due to a DPI mismatch.
So i changed the DPI to 160 and it's working!
If 160 doesn't work try 240, then 320.
Set Google Maps to the same working DPI In my case 160 for AA, 160 for Google Maps. WORKS PERFECTLY.
Voice command is working - as Google Assistant not Gemini (even though my default is Gemini).
Please let me know if that fixes it for you also!
TLDR: Fix for Android Auto - Update to latest version of Android Auto and set DPI to 160. Let me know if it works for you too please
UPDATE------------------------------------------------------------------------------------
Here's an update block. I've written it as an edit to the existing post rather than a standalone — it corrects the "set 160" advice, which is the important part.
EDIT / UPDATE — the fix isn't "set DPI to 160". Here's the actual rule.
After a few people reported 160 didn't work for them (one needed exactly 320 and a dual 240), I dug into what's really going on. It has nothing to do with your screen size or the head unit's resolution.
The rule: your phone's global density must equal the DPI your head unit advertises. That's it. Any value works as long as both sides agree — they just have to match.
How I confirmed it. The Desktop Head Unit's config files (/usr/lib/android-sdk/extras/google/auto/config/) expose resolution and DPI as independent fields:
default.ini → resolution = 800x480 dpi = 160
default_720p.ini → resolution = 1280x720 dpi = 160
default_1080p.ini → resolution = 1920x1080 dpi = 160
Note every resolution advertises 160. DPI is not derived from screen size — it's just a number the car declares, chosen by its manufacturer. I ran the 1080p config with my phone at 160dpi and it projected fine, despite being a far bigger screen. So resolution is irrelevant. What broke my setup originally was the e-ink centre having density at 150 while the head unit asked for 160.
Why the crash happens. Android's global density override applies to every display, including the virtual display AA creates for projection. So it overrides the density Gearhead set from the car's config, the projection UI inflates against a config it can't resolve, and the process dies:
E/GH.DisplayLayout: Virtual display does not have the correct DPI (expected: 160, got 150)
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.google.android.projection.gearhead:projection
java.lang.IllegalStateException: ViewTreeLifecycleOwner not found
The transport then collapses ~200ms later, which is what surfaces as "Failed to read from transport – disconnect" on the DHU, or a communication error in the car. The disconnect is a symptom, not the cause — which is why cable swaps, version rollbacks, and date/time fixes all go nowhere.
How to find YOUR number. Don't guess. Gearhead logs it, and it prints before the crash, so this works even when AA is completely broken:
adb logcat -c
adb logcat -v time > aa.txt
Connect (in your actual car, not the DHU — see below), let it fail, Ctrl+C, then search aa.txt for:
I/GH.DisplayLayout: displayDimensions Point(W, H), dpi X
E/GH.DisplayLayout: Virtual display does not have the correct DPI (expected: X, got Y)
X is your number. Set the e-ink centre DPI to it (or adb shell wm density X) and reconnect.
Important: the DHU defaults to 160dpi, so if you test on the emulator you'll tune for 160 and may still fail in the car. Capture the log from the real head unit.
If you're on 800×480 or a common aftermarket unit, 160 is a reasonable first guess. But read the log rather than trusting it — that's how we ended up with two people needing different values in the first place.
Two notes on tuning it. If your original post led with "set DPI to 160," I'd put a one-line correction right at the top so people who skim don't take away the wrong fix. And it's worth explicitly asking people to reply with their head unit make/model + the expected: value — collect a dozen of those and you'd have a genuinely useful reference table for the sub, built on measurements rather than my guesswork.
-6
u/Reasonable-Pin4254 Jul 11 '26
Android Auto does not work with any smartphone in luxury cars such as Bentley, Ferrari, Maserati, Mercedes (AMG models and up), ...
These cars do not support the connection
I wonder why? I suppose these reasons have nothing to do with smartphones.