Audi A4 B6 Courtesy System ECU

[a4_audi_ence]

Dear Forum,

After five years of trouble free service, my Audi A4 B6 2001/Y 1.8T Sport has developed a problem with its alarm and central locking system.

Symptoms:

Keyfob buttons will no longer unlock doors or boot

Manual insertion of key in drivers door will unlock front doors and boot but both rear doors seem to be deadlocked and cannot be opened from either the inside or the outside.

To cut a long story short....I have paid my local Audi dealer for diagnostics and their opinion is that the Courtesy System ECU, positioned in the passenger foot well under the carpet, has failed and needs to be replaced. They have quoted £400 for parts and labour to provide this service and I am currently debating whether to pay this amount or attempt a repair myself or go through a non-dealer garage.

Access to the unit and replacement looks quite straight forward but my Haynes guide warns that a new ECU will require initialisation by a dealer or specialist. So I would really appreciate the following advice:

1. Has anyone on the board ever purchased a Courtesy System ECU for this type of vehicle - if so, how much was it and where was it purchased from?

2. Does anyone have any experience of the level of "initialisation" required - and could a non-dealer garage be expected to provide this service? Indeed, is it something that I might be able to do myself? Are we talking programming by computer or perhaps just by onboard switch or jumper packs?

Thanks very much for any light you may be able to shed on this in advance.

Jon

[a4_audi_ence]

Sorry, correction to the terminology:

It's "Convenience System ECU"....not "Courtesy System ECU".

[warp_speed]

Access is easy stuff, however the ECU needs to be coded to tell it what options your car has, but I don't believe it needs to be coded to keys or anything. You need to get a hold of someone with a VCDS cable and software. They can code the module and get you going again, 5 mins job to code. These Convenience modules seem to be the bane of existence on VAG cars.

[a4_audi_ence]

Great advice, thanks, warp_speed. I understand that the dealer's technician initially tried to recode the existing Convenience System ECU but found that it would not play ball, leading to the diagnosis that the whole unit has died and requires replacement.

However, the information on VCDS, particularly that coding or initialising a new unit is a 5 minute job with the right tools is very helpful. I'll resist the temptation to ask where I can get my own VCDS and cable from, as I suspect that this will be all over the forums if it's such an essential piece of equipment......research in progress!

[warp_speed]

Actually there is a list on the forum.... somewhere that gives a list of people who have VCDS and their location. You could ask someone living nearby to help you out.

[RON MOODY]

Just a suggestion. Water ingress to the area where the unit sits is a common problem caused by the plenam chamber drain holes getting blocked. There is plenty of info about that on the forum (do a search). This sometimes corrodes the connectors and can also even rot away wires. Have a good clean up. Might be as easy as that!

[a4_audi_ence]

Thanks Ron, I have wondered about this because I did indeed experience blocked plenum chamber holes about two years ago - at the time a local garage tech talked me through unblocking the blocked rubber bungs to get rid of the water that I could hear sloshing around!

On the other hand, the Audi dealership technician made no mention of water underneath the carpets or around the ECU...and the whole footwell seems dry at a casual inspection level. I'll have another look myself, under the carpets, just to make sure....

[laur]

I had the exact problem as you,when I lifted the carpet it was soaking with water,I dryed the whole thing and the carpets and unblocked the plenum chamber but the ecu still didn't work so I took it out looked at the part no.and went on eBay hunting for about a week then found one with the exact part no.as mine for about 25£ second hand,fitted and everything started to work again except the remote key,used the forum to find a member with VCDS had the key readapted (for beer money )and evry thing is as good as new..Total cost=35 ish £..,good luck with yours.

[a4_audi_ence]

Thanks, laur....that's great advice. Been busy with work this week, but carpet-lifting to commence tomorrow on my A4! Very good to know that you were able to source a second-hand part so cheaply on Ebay....and I've found someone local with access to VCDS so I think I'm getting closer to a solution here....will advise progress for those interested....

[a4_audi_ence]

The outcome, for those it may assist in the future:

Had another inspection from a non-dealer local garage. Technician there confirmed that Convenience System ECU had failed, though not due to water ingress, all dry under the passenger-side carpet. Technician gave me details of the exact part number to source, and I found one of these on Ebay for £95. When the part arrived, the same technician was able to fit it and initialise it with the correct code using VCDS. Cost of labour £100.

So all now working again, including keyfobs, central locking and alarm for a total cost of £195, half the price the dealer quoted, quite chuffed with this!

Let me know if anyone needs more detail.....thanks so much for all your help to all who posted.