I have a 2005 superb comfort 1.9TDi (which I love) but lately she has developed electrical faults.

1. All my interior lights are gone along with my cill lights, external mirror lights and boot light. Only ones left are the 2 cats eyes above the rear view mirror.

2. On the central locking the car will not lock from the button on the key, but will manually when the key is inserted in the lock. It will unlock on the button.

3. My door open warning light is constantly on.

Can anybody help me? My mechanic and my local main dealer are having problems finding the fault? Has anybody out there experienced the same problem?

I would b grateful for any help.

Have you checked the carpets in the passenger footwell? If they are wet, then you have the cursed "Water Ingress" problem - it's a sticky topic which you can't miss.

syanide

Absolutely ... the control box that controls these lots of these things lives on the floor under the passengers seat .... just where the water likes to puddle as it flows in around the useless pollen filter seal.

My mechanic mate took mine out when I had a problem with a rear door not unlocking ( which turned out to be the lock) and there's a wiring loom that sits down on the floor as well. The connectors rust away as they sit in the water. He reckoned that mine were some of the best he'd seen (not much rust) and they sure looked a bit rusty to me!! Have since had the fix done on the pollen filter seal and the grommets, and all is nice and dry now ..... but I still lift the mat and check quite often.

O.K. thanks for the advice lads.

My mechanical ability goes as far as doing the basic checks and I wasn't sure whether the carpets felt damp or just cold, so last night I just pulled off the cill trims and got my hand down under the carpets to the floor of the car and lo and behold, WATER.

Now this problem has been going on for about 6-8 months which leads me to a question. How big is the damage? Will I most likely just need to replace corroded connectors or will I need to get a new convenience ECU? If I need the ECU is there anywhere online that I could buy one direct cos I rang my local dealer and he wants €850 (£700 roughly for one)?

You really just need to have a good look. Take the passengers seat out, lift the carpets and wedge something under them (they're pretty stiff) and just have a good look.

From memory, I think the control box unplugs and can be checked for water, but it's probably the corroded wires in the loom that are the problem. Be careful, and gently have a look at all the wires one at a time, making sure that if any are broken off, you know where they came from. New inline connectors can repair them.

In my experience, electronic boards and circuits that have got wet can often be dried out successfully, it's normally the connectors that rust away or "verdigris" (that green stuff) grows on them. A small, stiff glass fibre brush used in electronics for cleaning up tracks on circuit boards can also help.

Check that wiring loom first and then go from there. Also, check out the various threads for the fix for the pollen filter seal - VW agents should have the correct sealing strip, though they may well "not really know what it's for" because the problem "doesn't really exist .... Sir".

CRC

You are a true scholar and a gentleman sir.

Just one more question though to yourself or any other readers

If I need a new ecu are there any good places to buy one online at discount prices? This old recession is hurting me.

Answer is that I doubt it ... things like an ECU are pretty well bound to be "dealer only". However, I think you're looking on the black side ... a couple of hours spent unwrapping the wiring loom and testing / remaking each individual wire could well see your problems disappear.

Next thing to do is stop the water getting in there. For now, just lift the black plastic skuttle cover ( under the bonnet, between the engine and the windscreen, no tools needed ) and clear the leaves and debris out and while you're in there just think about what happens to the water that comes down the windscreen. It all goes through a tiny gap on the nearside inner wing and ends up in a big "well" that the battery sits in. Down there at the base of the "well" are two grommets, and they block with leaves and crud as well. Keeping the drainways clear is a big help to not getting water into the car.

Problem sorted. Love my superb again.

Thanks for all the help lads. Really appreciate it.

Problem sorted. Love my superb again.

Thanks for all the help lads. Really appreciate it.

Glad you got it sorted. Would you be kind enough to share what you ended up having to do please?

Thanks,

Syanide

Yeah no problem syanide.

Stripped out the plenum chamber, which was absolutely filthy. Threw away the grommets, removed the pollen filter housing, cleaned the whole area around it, sealed it back in using tiger seal. That was the easy part.

Found my convenience ecu swimming in a pool of water. It was knackered. I found an equivalent one in a breakers yard 120 miles away, so off I went to collect it. Cut all the wires back about 18 inches from the ecu and rejoined them in. Along with this I had to repair two wires in the loom. Unfortunately I needed to get main dealer help. The ecu needed to be programmed to my car which I didn't expect. All cost me €140 for ecu main dealer and all. Not too bad imo.

Thanks again syanide.