Bluetooth in Car not working since Samsung S4 update

[WhyMe]

So my Samsung S4 Galaxy Bluetooth has worked seemlessly with the integrated Bluetooth in my car since I got my phone a year ago. Just recently my phone stopped sending MMS (picture messages) so the Vodafone store told me to do a factory reset as it has something to do with a OS update.

I did the factory reset on the phone (which now sends MMS) but from that very moment my phone will not function correctly with the Bluetooth in my car.

Frustratingly, it connects perfectly as before even showing call logs and phone book as before but the very second I make or receive a call, the Bluetooth connection is dropped and the car displays 'No Bluetooth link'.

Furthermore, my wife has a Samsung S3 Mini which has also just stopped sending MMS but we chose not to do the factory reset on hers, and it connects fine to the car just as it always has, and it functions fine for her on both incoming and outgoing calls.

So it looks like there has been a series of OS updates, one of which will prevent MMS messages being sent, but should you then do a factory reset to get this facility back, you will lose In Car Bluetooth compatibility - really sucks, unless anyone else has any suggestions?

[hrym]

Assuming your contacts are sync'd with Google, they wouldn't appear on the phone until you log back into the account that has them.   If you want to preserve them, you could export them (there's an option in the Contacts app menu), then copy that file somewhere else, such as cloud storage to bridge the reset.  After you reset, import them from that file and you'll have them even if you're not logged into Google.  However, don't log back into Google with those contacts in place or you risk having everything duplicated when it re-syncs.   I'd do another reset to make sure they're nuked completely.

The fact that you can make Bluetooth work at certain points at least rules out a hardware problem.  It also suggests that there's isn't a compatibility issue with the BT version after the software update, which is something.

I agree, I can only conclude that one of your apps is doing something to BT.  It's odd that it affects all cars though.  Did we ever establish whether you can connect to other BT devices, such as a keyboard or a headset?

I have a BT pairing between my HTC One and my car, but I haven't tested it since the Lollipop update.   I'll try and remember to do that.

[WhyMe]

Hi @hrym!

Well the issue is RESOLVED!!!! but....not without other consequential problems!

Ever since I did the Factory Reset with my SIM card and micro SD card still inside the phone, and disabling the Google A/c at start up - the phone now works seemlessly with the in-car Bluetooth as it always used to.

I'm leaning towards it being a SIM card issue now resolved since this was the first reset with it left inside the phone although it still doesn't explain why the same SIM in my S2 continued to work fine.

So the only issue I now have is that the phone switches itself off and on several times a day without any consistent pattern (during a phone call, text messaging, using an App, or when I'm not even touching it). The phone feels 'sick and injured', the tocuh screen often lags or freezes, and some of the apps may crash or not open but I am happier dealing with this issue now that my Bluetooth in the car works.

So, I have three further questions...

1) Any ideas as to why the phone is now misbehaving (I have checked the battery isn't swollen as I read about this on the forums) - could it need a software update?

2) Should I ask for a new SIM card? I do actually have one but haven't authorised it yet. This very well may resolve everything but I have a slight concern it might drag me back to where I've been for the last 55 days.

3) A quick question for the Technical guys. Where is the information stored which remembers which photo I have saved as my wallpaper? Is this info on a SIM card, SD card, or Google A/C??

The reason I ask is that earlier this week when the phone initially worked after a factory reset, it would then drop the Bluetooth after the phone was switched off and on. At this point my saved wallpaper would appear and each time it did, the Bluetooth would fail in my car. Since I did the final factory reset with SIM and SD inside and disabled Google at start up, my wallpaper photo has not been downloaded and my Bluetooth has worked. This leads me to believe that where ever the memory settings were for my wallpaper also hosted the corrupt settings for my Bluetooth.

Oh and to answer your question @hrym - all along, my phone would connect with other phones and send and receive pictures via Bluetooth, and as it also connected with in-car Bluetooth until a voice call I believe there was a Bluetooth setting somewhere which was upset only by a voicecall.

It's been a journey of discovery and I'm still left astounded that Vodafone can corrupt my phone and leave on my own to figure out the problem, even more so when the Tech guys at Vodafone and at Samsung have been left bewildered as to what happened.

[hrym]

Thanks for the update.  This just gets weirder by the minute and it's a great shame Samsung never got involved as I believe they're the only people who could have solved this.   I'm not surprised Vodafone couldn't.

Quick answers to your questions:

1. It could be a batttery issue but, if it was, you'd also be seeing suspiciously short charge times (battery charge life gets short towards the end of their life).   The "sick and injured" feeling you describe sounds like a device that's short on memory.  Some Samsung devices have a built in task manager that also shows you RAM use and allows you to clear it.   Does yours and, if so, what does it show?

2. I can't see why a new SIM wouldn't hurt, though I'm reluctant to recommend anything, given the history of this!  Also, if the SIM was faulty, I'd expect it to be faulty in any phone.

3. The wallpaper setting is backed up on Google and one of the things that's restored when you sign back in to your account.

One final thought, if you're feeling brave(ish).  Do another reset, but don't sign back in yet.   Now go into Google account settings on the website and delete your Android backup (it's in Dashboard).   If there's anything in the backup that's carrying a corruption over (and I can't see what it would be), this will get rid of it.  You'll have to set everything on the phone (including wallpapers and signing back into all your wifi networks) manually, but it just might work.

I was going to say that I can't see why a voice call would upset Bluetooth, but I suppose it's possible the phone somehow thinks it's still in the car and is try to make that connection.   It's not something I've ever heard of, but this whole thing is barely believable in the first place!