Volkswagen Eos Forum banner
1 - 12 of 12 Posts

·
Registered
2010 Eos TSI Komfort DSG Automatic
Joined
·
24 Posts
Discussion Starter · #1 ·
Hi,

I have a 2010 Volkswagen EOS Komfort, and I recently had to replace the battery. I did so, but afterwards a number of things have been jumbled up inexplicably. For example, the way that I can access and browse the multi function display screen in the instrument cluster is no longer via the steering wheel mounted button controls, rather I have to place the intermittent windshield wiper rotary control at speed number two and wait three seconds at which point a list of control headings is displayed on the screen, at which point I have to put the intermittent coMyron back to position number one which activates the steering wheel mounted buttons on the right side which function in browsing the menu like before. And even this didn’t happen right away, it was about a month before the rotary control had any effect at all on making the menu appear. But that’s not really why I’m writing this post, my main problem is this: while the Bluetooth system still functions to connect with my phone and interface with the car audio, when I browse on the head unit to the media section, the Bluetooth button remains darkened and I cannot select it. In the set up menu, nothing is changed, there is still a selection box next to Bluetooth audio in, and selecting it or deselecting it, it makes no difference. I don’t have the Dynaudio system, I have the version That includes the Bluetooth master unit underneath the passenger side front seat, which has a main wiring harness connector as well as a removable Bluetooth antenna. I have tried everything I can think of, I’ve disconnected the battery and let it sit overnight after emptying the capacitance of all the electronics, checking fuses and relays and tracing wiring throughout the audio system with a multimeter to check connectivity as well as voltage readings when powered, there are no short circuits or freight wires or improper grounding, I even took it to my local VW garage and had them go in with a factory level VAG COM system in search of errors, then erase old codes and reset the system, all these efforts were to no avail.
If anybody is familiar with this sort of issue and how to fix it, I would certainly be in your debt.
-Jason
 

·
Registered
Joined
·
8,191 Posts
My guess would be adaptation settings configuring your car options have changed because the problems you describe seem option related. If you had your own diagnostics and had autoscanned all the car modules before this event, you would have something to go back and compare. Presumably your dealer scan found no faults?

They should have used your VIN number to identify the adaptation settings when it left the factory and checked if the long coding was correct? It sounds like they did the simplest thing which is scan and clear any error codes which hopefully did not come back? You need to go back and ask them if they used your VIN number to call up the V.W database and check your current coding settings against it. I'm surprised they were using VAG COM, because V.W have their own diagnostic kit starting VAS. Are you sure it was a genuine V.W dealership and not an independent or franchise with a V.W sign outside? Only V.W hold the original factory build data for your car which Dealers should be able to access.

If you are somebody has added options or replaced modules since the car was built, V.W would know nothing about that and somebody would have to go through all your adaptation settings.

I’ve disconnected the battery and let it sit overnight after emptying the capacitance of all the electronics
That doesn't always work because most modules incorporate a series protection diode in their power lines for accidental voltage reversal and internal memory could hold data with a residual voltage down to 1 Volt. But V.W via the mothership should have access to all the module binary files which allows them to reflash if there's corruption. If the wrong adaption codes are stuck there in NVRAM, they won't change unless a module is reflashed or re-programmed with the correct codes.
 

·
Registered
2010 Eos TSI Komfort DSG Automatic
Joined
·
24 Posts
Discussion Starter · #3 ·
thanks for your reply. But do you have any idea why simply changing a battery would create such a specific change in only the Bluetooth system, and then only affecting the audio transfer protocol while leaving the telephony functional?
To answer your questions, at the time of the battery change, there had not been any modifications to any systems in the vehicle. The only problem in the car was a faulty airbag control module
 

·
Registered
Joined
·
8,191 Posts
I always change a battery using a maintainer. I lose no settings or have issues caused by arcs, sparks, voltage spikes, or brownout on electronic modules.

If you have an electronic module that has a matrix of customisation (adaption) settings and firmware in its memory which sees an unusual voltage event, then anything illogical could happen. Such an event could in software terms break it to the extent the dealer can only offer you a replacement part. But as a last resort they may be able to reflash a suspect module, which in theory puts it back to factory settings.

If your Dealer is smart enough to get the original adaptation long code settings from V.W and check them against your car, you should get an answer without making guesses. The dash display only offers a minimal subset of option settings, compared to diagnostics.

If you aren't getting the right switches, buttons and on screen controls to work or show the right options, I think you have a software control or programming problem. If switches and buttons didn't work at all, that's more likely a hardware problem or faulty module and easier to solve.
 

·
Registered
Joined
·
103 Posts
A 9v battery and two wires will keep your car in check when removing the battery, but don't use one if you playing with the steering wheel due to the airbag...

 

·
Registered
Joined
·
8,191 Posts
A 9v battery and two wires will keep your car in check when removing the battery,
Not if you have the hood up, the doors open and the interior lights on, or door locks activate.

I use a 12V 2-3A series diode and over current protected mains d.c plug top power source. I also made a dc adapter lead using an old OBDII cable because my accessory sockets aren't permanently active.The video sensationalises what an airbag does when it's triggered out of the car to grab attention. I could do similar using a plastic Coke bottle full of gas.

In practice all yellow car airbag connectors are designed to short circuit when you disconnect them. Although V.W factory procedures require batteries to be disconnected for service work, the self shorting connectors provide additional protection, but I never hold an airbag unit in front of my face.
 

·
Registered
Joined
·
103 Posts
Well, it worked just fine for me.

Had the battery disconnected for a good hour with the bonnet and door open and all my stations/apps on my radio etc were fine afterwards.
 

·
Registered
Joined
·
8,191 Posts
These cars mine included, have a self locking security feature that catches many out: If the car is unlocked without a door opening for X secods/minutes, all the locks come on - try yours? I've often heard the locks come on when I hadn't done anything and wondered why. Some leave keys on the front seat or in the ignition and been locked out.

A standard 9V PP3 battery will not support the locks or interior light if they are on.
 

·
Registered
Joined
·
8,191 Posts
It comes on with the bottom door lights if you open any door, stays on, then dims. Your 9V PP3 will then crash down to zero volts.
 

·
Registered
Joined
·
8,191 Posts
I bench tested my new Android head unit which keeps its data just like my phone. Perhaps yours hasn't got a backup battery for its memory or your app is using volatile ram for its data storage? The DAB+ USB Universal dongle and App may be an issue which I haven't got to yet.

Even my old Chinese WINCE head unit kept its station favorites until last year when I had to replace its memory battery. Genuine VW head units do have radio codes which are mostly not needed because they check themselves against the VIN stored in the ECU when CAN is working. If you swap a radio to another VAG, you may need to enter the radio code.
 
1 - 12 of 12 Posts
Top