Bluetooth auto-connect problem
Thread Starter
Junior Member
Joined: May 2020
Posts: 52
Likes: 13
W212
Bluetooth auto-connect problem
I have a 2010 w212 with the comfort telephony option, and it had a phone cradle in the center console/armrest. I never used it because the car also has bluetooth integrated, so I always connected my phone through BT.
My phone always connected automatically to the car's BT, I didn't have to do anything.
A couple days ago I removed the phone cradle because it just took a lot of space in the center console.
The problem now is that my phone will not auto-connect to the car's bluetooth as it did before. At first it says "activating telephone" for a couple of seconds and then it says "telephone not inserted".
It never showed "telephone not inserted" before I took the cradle out, and there was never a phone inserted anyway. So I really don't know why it says that.
I plugged back the cradle in hope that the car will do its thing as before, connecting automatically to the phone through bluetooth, but it still does not. Again, it says "telephone not inserted".
I turned on and off the BT, the car, the phone, deleted and re-authorised the phone, but still nothing.
The phone just won't auto connect to the car's BT
regardless of the phone cradle being plugged in or not. I can connect it only if I go to "Tel" and click on my phone and then it will connect and it works just fine (even with the phone cradle unplugged), but only until the car is turned off. After I turn the car on again, the phone does not reconnect automatically. I have to connect it again myself everytime I start the car. It's really just annoying.
I read everything that I could find on the internet, and found that some people had this exact same problem, but the threads we're old and nobody figured it out...
Maybe someone now knows.. hopefully.
My phone always connected automatically to the car's BT, I didn't have to do anything.
A couple days ago I removed the phone cradle because it just took a lot of space in the center console.
The problem now is that my phone will not auto-connect to the car's bluetooth as it did before. At first it says "activating telephone" for a couple of seconds and then it says "telephone not inserted".
It never showed "telephone not inserted" before I took the cradle out, and there was never a phone inserted anyway. So I really don't know why it says that.
I plugged back the cradle in hope that the car will do its thing as before, connecting automatically to the phone through bluetooth, but it still does not. Again, it says "telephone not inserted".
I turned on and off the BT, the car, the phone, deleted and re-authorised the phone, but still nothing.
The phone just won't auto connect to the car's BT
regardless of the phone cradle being plugged in or not. I can connect it only if I go to "Tel" and click on my phone and then it will connect and it works just fine (even with the phone cradle unplugged), but only until the car is turned off. After I turn the car on again, the phone does not reconnect automatically. I have to connect it again myself everytime I start the car. It's really just annoying.I read everything that I could find on the internet, and found that some people had this exact same problem, but the threads we're old and nobody figured it out...
Maybe someone now knows.. hopefully.
Last edited by benidB; May 31, 2020 at 01:48 PM.
Senior Member
Joined: Dec 2018
Posts: 284
Likes: 60
From: New York
2010 E350 4Matic sedan
My guess is you would need to have the dealer update the software. Though I don’t have that phone cradle like you (not sure how that impacts BT), I do have a 2010 w212 that wouldn’t connect automatically to BT. I went to the dealer and had them do a software update for command. I’ve known other 2010 owners who also had the problem solved with a software update. That fixed the issue and now it connects automatically. I know your issue only started when you disconnected the cradle, but have you checked the BT settings in the engineering menu?
Thread Starter
Junior Member
Joined: May 2020
Posts: 52
Likes: 13
W212
There is not much that I can do in the engineering menu. I tried changing the device address For the phone cradle (The 12 characters combination). I once changed it to the phones address, and once just to a different random combination, but none of the cases helped. The same issues were present. I read in some thread that changing the device address for the cradle would Make the mb comfort telephone disappear, and that did happen to me too, but it also said that then it would reconnect automatically to the BT phone. Sadly that did not happen to me.
In a couple weeks I will need to take the car to the dealership for its B service so I’ll let them know about this issue as well, and ask them about the software update.
Thanks for the input
In a couple weeks I will need to take the car to the dealership for its B service so I’ll let them know about this issue as well, and ask them about the software update.
Thanks for the input
Thread Starter
Junior Member
Joined: May 2020
Posts: 52
Likes: 13
W212
So it came to mind that maybe a fuse was blown, and I checked and the telecommunication systems has 2 fuses, one in the front and one in the back. The one in the trunk turned out to be blown. It was a 5A fuse, and I changed it. For some reason the phone didn’t connect automatically if the phone cradle wasn’t plugged, but after I plugged back the cables from the cradle, everything works just like before. It first searches for a telephone for the cradle, doesn’t find anything, and then it searches for a Bluetooth phone and it connects automatically.
