Partial electrics issue/ Poss Changing Drivers Door Control Module

[nancol]

I have an Audi A4 2009 (B8) SE Exec which has lost some of its electrical functions

It started when I noticed a buzz/noise coming from the drivers door speaker and the drivers side top front speaker. Thinking it was water on a joint, I thought I need to inspect all joints when it stops raining!!

I then noticed the central locking had stopped working on the front and rear offside doors although the fuel filling door still locks. There are no lights on the window switches but all the window switches work okay. The remote control of both mirrors have also stopped working. Central locking via the key still works for the nearside doors and boot and the alarm sets with the LED flashing.

I started to inspect the various connector joints on either side of the A Pillar, inside the door (behind the door card) and under the seat, but everything is clean and dry. With the door card off I moved the cable joint between car and door around but no changes.

Whilst I have not done a continuity test on every wire on the loom, I can confirm a solid pos and neg reading on the two main wires connecting to the Door Module.

I am at the stage where I am suspecting the Door Control Module being at fault. The questions I have are:

1) Would such an odd combination of faults be demonstrated due to a faulty Door Module?
2) If I change the module with a working used module, does it HAVE to be commissioned to my car using a VAGCOM?
3) There is a lot of reference on the forum to the Convenience/Comfort Module. Where exactly is this and could it cause these issues?
(its is not under the seats so I am suspecting it could be near the battery on the engine side of the bulkhead?)

One last odd thing. The speaker(s) have started working again. However, if I open the door to its maximum on the strap, the noise appears. Close it a fraction and it clears. It is not the wires on the door joint, they have all had a good push/pull whilst testing. My guess is like an earthing issue when the door strap makes metal contact at its maximum opening.

Any answers greatly appreciated

Pete
Audi A4 Saloon 2009 2.0 (143) SE Exec
Exeter, Devon (with plenty of rain!!)

[Zenerdiode]

A lot of the functions you mention are provisioned by the door control module. It's just niggling that there are two doors (obviously with two separate DCMs) that have aparant faults. To attempt your questions:

1) Possibly. Hard to diagnose when I haven't got the fault-scan or my multimeter in hand. :)
2) You know where this is going... Even if the part numbers are identical, the 'colour code' of the module may be different. (The colour code is a three character code after the usual part number and sometimes denotes software or firmware levels.) Even if the Hardware and software part numbers are identical, the replacement module may have come form a donor car with some very subtle differences - folding mirrors, puddle lights, door red lights, interior handle illumination and suchlike. I think the answer is therefore yes I'm afraid.
3) CCM is behind the cover on the right hand side of the boot. Again, possibly, because it generates some of the CAN messages that are sent to the DCMs. (Ahem, *cough* - you'll not find the battery in the engine compartment; it's under the spare in the boot... :) )

Your speaker pop/crackle may not be directly connected to the speaker wiring; it may just be picking up the electrical interference from something else.

[nancol]

Many thanks for your input with my problem - Sounds like a trip to the Audi dealer is on the cards very soon!

Just a couple of points and questions:-

- Thanks - I didn't realise the battery was in the boot. On my previous A4 it was near the bulkhead! - how easy to assume!!

- Are the speakers effectively "direct connect"? If so, I really do need to investigate this situation where the speaker changes to a buzz when opened against the strap maximum point. Wondering now if a wire is being trapped in behind which I will have to remove the speaker to find!

- as an aside reading through other threads, would there be an option on my A4 B8 to set the nearside door mirror to dip when I select reverse?

- As a computer engineer with an electronics background, I feel I am wanting to interrogate my CCM and car options in a bit more detail. Can anyone suggest a good place to start with regards to the OBDII hardware interface for my laptop and appropriate software without going over the top??

Thank everyone!

[Boy]

Pete,
see the diagnostics section of this forum.
You need vcds which with your skills will unlock all of the
wrinkles you need to know.

[nancol]

Thanks will take a look in the diagnostics section

I guess if someone can point me at a circuit diagram I can confirm my question re if the speakers are "direct connect" all the way through from radio/amp to each speaker

Great forum thanks
Pete

[Zenerdiode]

Here's an excerpt from a generic drawing for the front driver's speakers on the A4 B8.

18951

[nancol]

Thanks Zenerdiode - this looks quite helpful but I cannot read the detail as it blurs when I make it slightly larger. Any chance of a better size image please?

[nancol]

Well I have a breakthrough with this issue!!

Stripped the door down again AND removed the speaker. Discovered that the wiring loom was being trapped and crushed by the door strap when the door is on maximum opening. Three wires were completely crushed, broken open and melted together but managed to repair them all.

Put everything back together but no change. My guess is the Door Control Module is shot as a result of being shorted!


What I did find inside the door and full of water is a rubber boot/gater which I assume should be fitted to the back of the strap fitting

[gupsterg]

Looks like you won't need the diagrams... again sorry I thougth the info was for a mod,etc had not seen this thread until your post now :Blush2:...

Sorry you had fault :( but great you sussed it :) ...

[sportq]

Well I have a breakthrough with this issue!!

Stripped the door down again AND removed the speaker. Discovered that the wiring loom was being trapped and crushed by the door strap when the door is on maximum opening. Three wires were completely crushed, broken open and melted together but managed to repair them all.


Reviving this old thread as I think I have a very similar issue. The heated door mirror on the drivers side of my 2009 Avant has never worked. I know it's not the mirror as I removed it and tested it with a bench 12V power supply and it warmed up as expected. Now the indicator in the door mirror is not working an flagging a bulb error in the DIS. It's intermittent though as it started working briefly at the weekend so I know it's not actually the bulb (are they LED's?). I suspect after 180,000 miles of door opening and closing the loom is damaged.

Anyone replaced the loom that passes between the car body and the door? Is it a simple job to replace or is a repair a better option?

Pete

[nancol]

With regards to repair or replace, it depends how many wires are damaged or broken. I ended up repairing three wires then found another two that were damaged and access is not that easy when trying to work on the wires. If you replace, you have to get to all the clips and ties and bear in mind the cost of a door loom!! Either way quite time consuming.

Peter

2014 A4 2.0TDi Technik Saloon, Brilliant Red

[sportq]

With regards to repair or replace, it depends how many wires are damaged or broken. I ended up repairing three wires then found another two that were damaged and access is not that easy when trying to work on the wires. If you replace, you have to get to all the clips and ties and bear in mind the cost of a door loom!! Either way quite time consuming.

Peter

2014 A4 2.0TDi Technik Saloon, Brilliant Red

I see a few drivers side door looms from savaged vehicles on ebay but they're likely to be worn too. I think I'll go the repair route and give the repaired cables some extra protection with kevlar tape.

Peter

[nancol]

Yes I agree regarding a loom from an old car unless you were lucky to find one at a breakers with low mileage. As long as you have time to work through each wire and check them out, a repair with kevlar tape should do nicely. Good luck!

Peter
2014 A4 2.0TDi (http://www.amazon.co.uk/-/dp/B00274M76M) Technik Saloon, Brilliant Red