Help! Samsung Galaxy S6 bluetooth problem when connecting to car

[AC Question]

Hi all,
After having issues with my Huawei P8 when connecting to Bluetooth devices such as jaybirds v2 and my car Bluetooth I decided to sell it and upgrade to the Samsung galaxy s6 which is meant to be one of the best and strongest phones on the market.
The problem with the Huawei P8 was that it had very unstable and weak signal when connecting to Bluetooth devices and every time I would turn on the option to sync contacts to cat Bluetooth that phone will get stuck.
After changing to my new galaxy which I am very pleased with in the beginning it seemed to be perfect, no connection problems with the Jaybirds v2, stronger signal and it also connected to my car and uploaded all contacts and phone logs with a matter of seconds.
The problem stated a day or two later, every time I would connect to the car the audio and media won't work at all and not upload any new contacts or phone logs. After fiddling with the phone a bit and updating both phone and the system in my car i figured out that the phone audio and media connection will suddenly only work if the sync contacts option is off and i didn't understand why this suddenly happened... one day everything was working smooth as it can be and the next not at all when the contacts option is on.
What I did to try to get it work is format my new phone completely as well as my car audio system. Formatting my phone worked for a day with everything and i was happy as I could be but then a day later it stopped working again when contacts sync option is on, now I figure it might be an app that I installed both times but I have no idea how to trace which one it is.... Or maybe it's just something else that I turn on or off..

If anyone has any ideas I would be grateful as it is driving me nuts!!

Details:
Phone: Samsung galaxy s6
Car: Dacia Sandero
Audio system: medianav

 

[B. Diddy]

Welcome to Android Central! Is the wi-fi radio on? Wi-fi can sometimes interfere with Bluetooth, so see what happens if you turn off wi-fi (even though it's in your car).

 

[Ben Baker Morag]

Welcome to Android Central! Is the wi-fi radio on? Wi-fi can sometimes interfere with Bluetooth, so see what happens if you turn off wi-fi (even though it's in your car).

Hi thank you very much for the quick replay! I tried turning both wifi and location off and did not do anything. I would also like to mention that altough it shows both on the phone and medianavi that there is a connection, the phone plays sounds and receives calls as if there is no connection.
Would be grateful for a solution!

 

[B. Diddy]

Go to Settings>Bluetooth​, select the Bluetooth device, and make sure Phone Audio and Media Audio remain checked on.

 

[Ben Baker Morag]

I made sure. They stay on but don't work. I think it might be an app but not sure how to track it down.

 

[B. Diddy]

Does it work in Safe Mode? If so, then you're right, it's probably a 3rd party app. Unfortunately, it's tedious to troubleshoot--you have to uninstall apps one by one until the problem goes away.

 

[Ben Baker Morag]

i tried deleting all the apps and it did not work. I then formatted the phone which worked last time, but this time it didn't, I think I will just give up and live with it the way it is unless anyone has any other ideas...

 

[B. Diddy]

Hmm. Do other Bluetooth devices work smoothly with it, or do they also have intermittent dropout? If the latter, then I'd wonder if there's something wrong with the phone's Bluetooth radio.

 

[Ben Baker Morag]

All other devices like my Garmin smart watch and my jaybirds x2 seem to work fine, the thing is that so does the car system until I turn on the contacts sync. any ideas

 

[B. Diddy]

Grr. I'm starting to run out of ideas.:-\

I assume that Media Nav system is factory-installed. Is there any option to upgrade the firmware?

 

[lucianus_luciferus]

Tried Clear cache on the contacts app?
Where are your contacts saved to? Google account? Phone?

 

[Ben Baker Morag]

Google and phone and ya, I tried!. But I'm happy to say that it suddenly started working!! Have no idea why. Will keep you up to date if it stops

 

[Eric M4]

i tried deleting all the apps and it did not work. I then formatted the phone which worked last time, but this time it didn't, I think I will just give up and live with it the way it is unless anyone has any other ideas...

I am having similar issues with my s6. I thought it was the WiFi connection that was dropping the Bluetooth, but that hasn't been consistent. What I have experienced is that my music will play through Bluetooth, until my WiFi disconnects (when I pull out of the driveway). My car says it is connected to media and call audio, but the media plays from the phone not through Bluetooth. Today was slightly different. I was casting a video using chromecast and chrome Web browswr, then got in my truck, Bluetooth connected, audio playing through Bluetooth with Samsung music, pulled away and WiFi disconnected, music still playing, and when I closed my browser, the music started playing from the phone.

I have tried turning off WiFi prior to connecting and that seems to solve the problem. This is new though I have had no issues with Bluetooth or WiFi in the past, and it's pretty annoying to have to turn WiFi off and on for the phone to function properly.

 

[JillSC]

I'm having the same problem. I've had my car for 10 months and suddenly the contacts and call history stopped transferring a couple of weeks ago. I've tried everything - removed and re-added the phone a dozen times, rebooted the phone, tried my husband's phone in my car (works), tried my phone in his car (works), tried deleting recent apps, tried turning off WiFi, tried unpairing all other devices from bluetooth. I've pretty much done everything short of a factory reboot on my phone which would be an absolute last resort. Obviously the problem exists only between my car and phone. The car sees how many contacts I have because it will say 0/93 or however many...they just never transfer. Does anyone have any ideas that I haven't tried? Now that I unpaired the devices I lost my contacts in the car altogether. This is exceedingly frustrating! Thanks.