Audi A4 Roof/Electric Windows not working

[Paul Falcon Cars 3]

I have a 2003 Audi A4 Cabriolet, the battery has recently gone flat , I have charged battery, started car to find the roof, electric windows and key remote not working, if I disconnect the battery and reconnect it all comes back to life for a short time and fails again.

All the other electrical units work, wipers, radio, horn, lights, etc.

What can be the problem?

[MarkTVS 209]

Have you tried relearning all the windows? Is the battery passing tests?

[New year revolutions...... 197]

1 minute ago, MarkTVS said:

Have you tried relearning all the windows? Is the battery passing tests?

Well the battery on my car failed its spelling test,I put it down to underperforming and not firing on all cylinders,or was that my school report

[Paul Falcon Cars 3]

Tried it all including programming key fob. 

[New year revolutions...... 197]

15 minutes ago, Paul Falcon Cars said:

Tried it all including programming key fob. 

Is the comfort module behind the seat on these and wet.?

[Paul Falcon Cars 3]

Havent checked that, the car has been garaged for a couple of months and is bone dry inside.

Which seat is the module situated?? 

[Halfpenny 114]

This is a fairly common fault on these although thankfully its a while since we've had one in. Water ingress into comfort control module (located passenger side). Often the carpet is dry but dig down to the module and its soaking wet.  Water usually gets in via the rear cover that goes over the roof.  You need to get the module out and try to dry everything, check connectors and check for rotted out wiring. If its been wet a long time it may be past fixing - and of course they are not cheap.....   If you get it working suggest you get a new battery too - they can be temperamental if the battery is not in good shape. You may need to reset the roof with a manual close/open (ign on).  The roof motors are also a bit crap, brushes wear quickly and also can get wet and fail.  Not my favourite cars..

[Paul Falcon Cars 3]

Really appreciate your comments, I will check out in the morning. 

Is it located in the front or rear?? 

3 hours ago, Halfpenny said:

This is a fairly common fault on these although thankfully its a while since we've had one in. Water ingress into comfort control module (located passenger side). Often the carpet is dry but dig down to the module and its soaking wet.  Water usually gets in via the rear cover that goes over the roof.  You need to get the module out and try to dry everything, check connectors and check for rotted out wiring. If its been wet a long time it may be past fixing - and of course they are not cheap.....   If you get it working suggest you get a new battery too - they can be temperamental if the battery is not in good shape. You may need to reset the roof with a manual close/open (ign on).  The roof motors are also a bit crap, brushes wear quickly and also can get wet and fail.  Not my favourite cars..

Really appreciate your comments, I will check out in the morning. 

Is it located in the front or rear?? 

Really appreciate your comments, I will check out in the morning. 

Is it located in the front or rear?? 

[D&M 66]

May not be relevant, but we had an A6 not so long ago - the comfort module was wet and giving us funny symptoms.

Sure enough, under the carpet was soaked - took about 10l of water out. Carpet was dry, but you could hear the water sloshing!

On the A6, it was under the carpet where the passengers feet would be. Black box about the size of an A5 sheet of paper and an inch thick.

We took ours out of its plastic casing (full of water too!) and cleaned all the circuit board with a toothbrush and contact cleaner and left it in the airing cupboard overnight to dry properly.

Lucky enough, that sorted all our issues. Hopefully yours will be as easy as that.

[Paul Falcon Cars 3]

Really appreciate your help, will check out today and get back to you. 

[Halfpenny 114]

IIRC on the A4 its pass side footwell.

If it turns out not to be wet there are other possible faults. These are a fragile system. Even a bad door switch can stop it working. VCDS will help - everyone dealing with VAG cars should have it.

[Paul Falcon Cars 3]

Okay, so I have taken the soft touch model out and floor pan and modual is bone dry, and no corrosion on connections. 

This problem only stated when the battery went flat. 

The only way I can get it to work is disconnect battery, reconnect, put key in ignition and turn on, it then works perfectly until left for an hour, then fails again. 

[Halfpenny 114]

As I said before, this is a fragile system. We have had a lot of A4s over the years with faults related to comfort module.  Look for broken wires at door hinges and faulty sensors (roof position sensor, door switch). The module itself could be faulty. Can you scan it with VCDS ?

[Stalker 180]

Have you tested the battery to see if it is ok? 
Is the alternator charging the battery? 
Do you have the engine running whilst operating the roof/windows? 

[Paul Falcon Cars 3]

Hi 

Thanks for your suggestions. 

Yes, done everything but cure it. 

[Paul Falcon Cars 3]

Hi 

I have finally traced the central locking fault to the Comfort Modle, Halfpenny and a few others sujested this, but the Modual is bone dry!! 

My question is can I replace it with a second hand one, if so, how do I program the keys to it?? 

Paul. 

[Halfpenny 114]

20 minutes ago, Paul Falcon Cars said:

Hi 

I have finally traced the central locking fault to the Comfort Modle, Halfpenny and a few others sujested this, but the Modual is bone dry!! 

My question is can I replace it with a second hand one, if so, how do I program the keys to it?? 

Paul. 

Yes, you can replace with s/hand.

Code the module and program the keys on Channel 21 as per this link:  http://wiki.ross-tech.com/wiki/index.php/Audi_A4_(8E)_Comfort_System

As to it being bone dry but faulty - well, its 17 years old and they weren't all that reliable when brand new!

Edited March 21, 2020 by Halfpenny

[Paul Falcon Cars 3]

Really appreciate the comment, thank you. 

So, presumably you can't code manually?? 

[Halfpenny 114]

58 minutes ago, Paul Falcon Cars said:

Really appreciate the comment, thank you. 

So, presumably you can't code manually?? 

TBH I don't know. We have had Vag-Com/VCDS for many years so never tried manual coding.

[Paul Falcon Cars 3]

Okay, thanks for that, I will get second hand unit and go from there. 

 

[Paul Falcon Cars 3]

Hi all

Ongoing saga with A4 remolt. 

I have been offered a Comfort modual out of a A4 convertible same but different part number, can anyone tell me if this modual can be programed to the car??

[Halfpenny 114]

On 3/24/2020 at 7:39 PM, Paul Falcon Cars said:

Hi all

Ongoing saga with A4 remolt. 

I have been offered a Comfort modual out of a A4 convertible same but different part number, can anyone tell me if this modual can be programed to the car??

As far as I can recall we have always matched part numbers so I cannot say one way or the other. My experience with VAG electronic modules in general is that different P/N does not work.

[Paul Falcon Cars 3]

Appreciate you getting back to me, will source matching number. 

Paul.