CCU problem ... what now?

[Glenn Langridge]

Hi everyone, I'm new here tonight after lurking for a few days taking notes.

I've bought a 2003 A6 1.9 TDi Sport Avant recently with a few 'issues'. I want to see if I can crack some of these problems before resorting to the skills of a professional.

OK, the car has the common non-functioning key fobs most likely caused by a faulty CCU. I have to unlock the door via the key but only the driver's door unlocks and I have to get the key in the ignition sharpish before the alarm goes off.

Anyway, I lifted the passenger side carpet and it was pooled with water underneath. The water stank of screen wash which I traced to a loose fitting connection going to the rear squirter. I sorted that out, drained the water from the footwell and removed the CCU. I couldn't see any water or corrosion in the CCU but I let it sit on a sunny windowsill for a few hours to air anyway.

I also removed the battery and cleared the blocked drain holes in the scuttle while I waited then put it all back together and refitted the CCU.

The central locking now seemed to work and I was able to resync both fobs with no problem. I was the happiest bunny for the next few minutes until the fobs and central locking stopped working again. No amount of disconnecting, cleaning, reconnecting and wiggling would make it work again. Damn!

I did notice that part of the CCU had got quite warm within minutes. Is this to be expected?

So, where now? Is there anything more I can do before resorting to buying another CCU and engaging the skills of a pro?

[JimC64]

Hey Glenn, dunno if you have or not, but have you tried a search of "CCU" or "water related issues" etc etc to see what others have tried to resolve the issue?

Just a thought mate and only trying to help

[Peter D]

Actually it is CCM and the plenum chamber. You need to dry the carpets and underlay out as it sounds that you have water in the cable harness. This can take TWO days with blocks of wood to lift the carpet and a 1kw heater blower suitabley and safely positioned.
Or you remove the seat. You may also find water under the rear carpet as there is recess to the rear that house the rear heater air duct. Regards Peter

[Glenn Langridge]

Thanks for the replies gents. I didn't realise it was called the CCM ... there's so many variations out there on the net (CCU, CCM, Comfort Control, Convenience Control, Central Locking Control etc) that it makes searching a pain.

I guess I need to let the drying process continue for a while. I'll get the hair drier on the harness later when the rain stops. Could really do with some nice, sunny weather though to get it properly dried out. And I'll check out under the rear carpet while I'm at it.

If the CCM proves to be FUBAR'd is the next step to pick up a replacement (eBay, breakers yard etc) and have it matched to the vehicle by a suitable pro with VAGCOM/VCDS?

[mrnice]

Hi, been through this stuff in last few months, I haven't resolved the remote locking issues but i did a long post about preventative stuff with a few pics here:

Blocked drain holes on a6 c5 2.4 auto avant flooded interior - Page 4

I know you've done most of this (and my solutions are a little 'pikey' but there may be useful info,

cheers and best of luck

[Glenn Langridge]

Thanks for the replies gents. I didn't realise it was called the CCM ... there's so many variations out there on the net (CCU, CCM, Comfort Control, Convenience Control, Central Locking Control etc) that it makes searching a pain.

I guess I need to let the drying process continue for a while. I'll get the hair drier on the harness later when the rain stops. Could really do with some nice, sunny weather though to get it properly dried out. And I'll check out under the rear carpet while I'm at it.

If the CCM proves to be FUBAR'd is the next step to pick up a replacement (eBay, breakers yard etc) and have it matched to the vehicle by a suitable pro with VAGCOM/VCDS?

Thanks for that link mrnice ... I'll definitely be following your advice. I like the idea of the pollen filter cover a lot so am now on the look out for a suitably sized piece of plastic.

[Glenn Langridge]

I've now taken the passenger seat out and lifted the rear carpet and there was enough water in the back to float a boat so good call PeterD. I've mopped it all out, and squeezed as much water out of the carpets as possible so now I need to dry out what's left. So I need to find a suitable heater or dehumidifier. A bit of sunshine to warm and dry the ambient air would be helpful too.