Audio 20 losing phone pairings

[HumberMart]

After a year of owning her new B180, my wife is at her wits end with the constant need to re-pair her Samsung F400 with the bluetooth.

For the first few months, the phone would stay paired for weeks at a time, and then just simply disappear from the phone list. The same happened if I paired my N95 8GB.

The dealer has tried 2 software updates, and replaced the BT unit, but the problem has got worse. It now loses all recollection of the phone after about 4 hours. However occasionally it will not lose it for a couple of days.

They have just about got permission to replace the head unit from MB, but MB seem insistant that it's a compatibility issue with the Samsung. I've fought this, since it also loses my N95 which is supposed to be compatible, and her Samsung stays paired with no problems, to my E220. Also, I fail to understand how it can be a compatibility issue. It simply works fine for a few hours, days, or weeks, then loses all trace of the phone. A bit like the internal battery back up in the unit is failing.

I was very sure of my stance, until she borrowed a loan A Class today, and it lost her phone from its memory after about 2 hours!

I've Googled this issue as best I can, and searched the forum, but it seems strange that I can't find any other examples of this phenominum.

Surely someone must have experienced something similar

(This is our 4th Merc in the last 3 years, and we've never had this issue before, but typically the technicians at the dealers have never managed to get the fault to occur whilst it's been in, even over a 3 day period)

 

[st13phil]

You have my sympathy.

My experience of Bluetooth in general is that it's the carpest "standard" on earth. The fact that manufacturers publish compatibility lists for Bluetooth devices tells me that the standard is too loose and/or poorly implemented as a matter of routine. Whether it works properly or not is too dependent upon the chipsets that the devices use and the firmware stacks - so much so that I always treat it as a matter of luck when Bluetooth devices pair properly and work reliably together

A couple of obvious questions, though: have you done any firmware updates on the phones since the time that the pairing was reliable? For example, my Nokia E72 would pair perfectly with the Audio20 in my W204 and I could make and receive calls, but at indeterminate intervals during a call the audio in the car would mute and the other party would hear the car's radio(!) then, after about 20 seconds, the audio connection would resume. After a firmware update on the phone all is well.

 

[HumberMart]

Good point Phil, I hadn't thought about a firmware update on the phone - although I'm pretty sure my wife has never tried to do it!

However I still puzzle over the way it is the head unit that loses the memory of the phone. The phone still retains the MB details regardless, so I would doubt it could be affected by the phone's firmware.

Having said all that, I did use her car once when it lost the pairing after I had previously been the last person to drive the car when it was paired (so at least I've seen it with my own eyes), and I was almost sure that just before it lost its memory, the pairing details flashed up on the Audio 20 just for a millisecond. I guess this could mean that it actually hasn't lost its memory over night, but loses it the instant it tries to re-pair with the phone (on some occasions only). I suppose on these terms, one could begin to understand that it is the handshaking it gets back from the phone that causes its memory loss, and maybe therefore compatibility is a feasible cause.

The plot thickens....................

 

[npuk]

It is like the headunit is losing its permanent live feed and forgetting its settings but they you posted above it has done whilst on too. Have you checked if it is losing the radio presets etc.