Audi A4 B6 - Electrics going mad!!

[Ray Singh]

Hello All.

I have a 52 plate Audi A4 - B6 shape 1.9tdi - its been a trusty car for over 155k miles.
Over the last few weeks its deleloped a tendancy to go mad. It tells me bulbs are not working, when they are and locks unlocks doors at random. I had a similar problem with my B5 a few years ago and it was down to water ingress into the ECU.

Please can you tell me how i can check if this is the case? Where is the ECU on a B6?

Thanks.

[swampdonkeygj]

I used to have one of these. It could be the module underneath the carpet in the passenger footwell, I think it's called the convenience module. There is a drain underneath the battery in the engine bay which gets blocked. That then fills with water and it leaks into the car apparently, causing issues with the electrics. I seem to remember the drain bung is directly underneath the battery and it gets leaves trapped in it. I removed mine.

Take a look where your battery is and see if there is any water in the tray.

[Ray Singh]

I will do this now - thanks :-)

[Ray Singh]

Nope, all dry under there!

[swampdonkeygj]

Oh well worth a try.

Have a look at audi-sport.net or vwaudiforum.co.uk you should find something there.

[oldaudi]

Is it something as simple at the battery not holding its charge. Mine started to do things like this, being tolds that bulbs broken, get of the car to check and the bulb was working, clock resetting itself and the ABS Read warning light on the DIS.

Checked the battery and it was on its way out, replaced it and its all been fine since. This happened on a B6 A4 180K miles 2001

[Ray Singh]

So i handed the car to my local mechanic. He has read out the fault code and the steering angle sensor has gone. Part alone is £200 and an hours labour to fit.

Would this cause the ABS and ESP warning lights?

R

[Dr G]

Yes, it can - ABS & ESP are closely linked systems.

If you even suspect a convenience ECU fault with a B6 you need to have a really good look in the scuttle tray (under wiper rack, back on engine bay) as it commonly clogs with old mucky leaves, particularly under the battery and can allow water to get into all sorts of places you don't want it. Even if the carpet is dry now have a really, really good look in this area.

[k20erham]

Don't just feel the carpet pull it up and check underneath, got a funny smell yet? or do the windows mist up really easily?

[Ray Singh]

Yep - you guessed it....

The windows have been opening themselves recently. This lets all the rain into the car. When i get in, it mists up.

I will check this area once the Steering angle thing has been done this afternoon.

[k20erham]

Interior lights doing funny things too? really does sound like water ingress somewhere, I would have a really good sideways glance at the steering angle sensor/ work your having done now, once water gets in everything can lie, even if vagcom says different, don't be surprised if today's work does not cure your issues!!

[Ray Singh]

Steering angle sensor replaced - part alone around £200 and an hours labour to fit. Walked out £300 lighter.
No warning lights on dash, felt relived that all was well.

On the short commute this morning, the ESP light came on again.....Argh!!!

I will take the car back on Thursday afternoon and keep those of you who care, updated.

[k20erham]

arrrrrrrrrrrr so so frustrating, please investigate further for water ingress damage diagnostics are only as good as the tech using them, and unfortunately an error code can often be very misleading and expensive. But always will to learn please keep us posted.
I've got the latest Delphi gear that lets me gather live data on the fly (drive) near Hammersmith if you're ever about

[Ray Singh]

As per one of the initial suggestions - I changed the battery on my car. Eurocarparts Bosch Silver - approx £110.

All warning lights have gone out and the electrics are all sorted.

I cant help feeling that the £300 i spent on getting the steering angle sensor fixed was a false alarm.

You live and learn.....

£300 though,.... FFS