A reset to factory settings will clear everything from the phone. Returning it to it’s original condition, as if you’d just got it out of the box for the first time.
Unfortunately it’s a rather extreme measure, but the only way of knowing whether it’s the current Android version causing this issue for you.
As Wardy suggests a reset, I did that on my Motorola but it didn’t roll back it back to Android 14, reset with Android 15. Not sure if it’s the same with Samsung phones?
With this thread still active and it’s raining I’ve just tried a number of different settings on my phone plugged it in, nothing, it won’t connect. I’ve been on the internet too delving into all sorts of tech sites to no avail.
Connect my other older Motorola (android 13) and it connects instantly. I’m well out of ideas.
That’s a good point Mick. Depending on how the upgrade to Android 15 has been prepared, it’s possible that the default image on the phone has also been upgraded. This approach may differ between phone manufacturers.
It’s still technically possible to revert to an earlier Android version, but it does get a bit technical unfortunately. It involves accessing the Bootloader on the phone and then installing the previous Android OS version via your PC.
General steps are set out here if you’re interested:
How to Downgrade from Android 14 to Android 13 – TechCult
I used to do quite a bit of this, but nowadays I just use a Google Pixel which are straightforward from an Android OS perspective and things tend to ‘just work’ - e.g. running Android 15 and having working Android Auto in both a Mazda & BMW 
I’m using a Samsung A52s witha Pioneer Double Din unit in my Audi, and I often have to clear the cache. But recently the system has stopped relaying the voice from the phone/Pioneer during a phone call, it works fine for satnav and radio, but just wont play the audio from a phone call. My ICE expert says that AA is basically c**p and the best syetm is Apple Car Play, so I’m probably going to move to an iPhone.
My phone is running on Android Ver 14, Samsung say that this is the latest version?
Sounds a bit technical for me 
I think I’ll leave it as is and see if I can borrow an older phone to try.
Just a little update, I tried a friends phone this morning, A54 I think and it connected first time, not going to replace my phone so it looks like AA is off the cards until I update the phone 
I might have missed it, but have you used the original lead supplied with the phone?
Yes, and a good quality lead aswell, my friends phone was connected using the quality lead.
As suspected, but at least you have confirmation of where the issue is now 
Just a little update, I updated the phone to Android 16 this morning and unfortunately it still doesn’t connect.
Last weekend whilst my older phone was charging I switched on my newer phone, the one that won’t connect to AA. It updated after a few minutes, security update and some other fluff that I take no notice of. Tried it in the ND, nope still no workey.
Such a shame 
Is it worth logging a technical support ticket with Samsung and Motorola respectively, regarding the lack of functionality?
I wonder if there’s opportunity for you both to try the problematic phones in another ND at a future meet-up/event, to rule out it being the individual modules you each have fitted 
My friends older Samsung worked OK, my partner has a slightly older lower spec version of my phone and that doesn’t work either, the fact mine worked until the android 15 update suggests it’s that that’s the issue more than the phone I think.
Understood.
However, it’s important to note that this isn’t purely the A15 or A16 OS update issue alone, more Samsung (and Motorola)’s implementation of it on their hardware.
As I might have said before, for me Mazda (and BMW) Android Auto functionality has remained unchanged through both these OS updates, on a Google Pixel device.
So raising this as a support issue with Samsung might at least give them more visibility of the issue. As I’m sure they’ll respond in a way that will feel like you’re the only user of that handset to be experiencing this issue (!!)
I think for me anyway, other Motorola users have logged their issues with Motorola tech support re AA connection issues and other problems. The one noted issue is updating to Android 15 that’s may have caused these issues or buying said phones with Android 15 already installed.
I’ve seen posts on these tech sites relating to all the issues, it seems Motorola only send you round in circles with their advice, reboot, reinstall, check this setting check that setting etc. If it’s got a setting I’ve set it, if it can be reinstalled I’ve done it etc etc. It’s the same on the AA tech support, I think one even said sorry no support for the Mazda connect pre 2017
Probably mentioned this before, both phones I have work perfectly in my Skoda Kamiq with AA, just the older phone (Motorola) works perfectly in the ND with the AA module. I’ve yet to try any iPhones, I don’t have one to see if car play works or not in the ND.
My phone works perfectly in my VW.
I have the same issue. What is weird is that AA it got detected by the car (warning to accept it) but now does it only charge.
Running OnePlus 13 with Android 15.
Version number: CPH2653_15.0.0.864(EX01)
It works now with my old phone (Oneplus 7t Pro).
Red original lead connects with a high rate of success. Usb c to c lead works to but not such as high success rate.
It works now with the OnePlus 13, running CPH2653_16.0.5.703 (EX01).
Note that you need the USB-C to USB-A adapter to force USB 2.0, or you need a USB-C cable that max support USB 2.0
Also i have set Default USB configuration to File transfer / Android Auto in Developer Options.