Air Conditioning - blows hot and cold + ignition key fault

**westiej** · 15-04-2011,02:18 PM

I'v got a '54 plate TDi SE, and there is a very strange fault with the air con. When I turn it on it will blow nice cold, conditioned air from the vents in the centre console, but absolutely boiling hot air from the vents by the doors. This fault seems intermittent, and I'm pretty sure can swap which vents blow hot/cold, or all of them can.
Anyone any idea what might be causing this?

My second problem is that when I switch off the ignition, it isn't always recognised. You can tell as the big clunk you normally hear doesn't happen, radio stays on, and the doors won't work from the remote. This is also intermittent and much worse in warm weather - in fact it doesn't happen in the winter. Will normally behave if I turn the key off and on a few times.

Any help you can give will be greatly appreciated. TIA, John

Getaway_Driver · 15-04-2011,02:34 PM

The air con issue is quite common - see this thread:
https://www.vwaudiforum.co.uk/forum/s...lenith+chamber

Check the part number on the heater valve, if it's 4F2 959 617 A then most likely it's the old one. They were replaced by 4F2 959 617 B.

with regards to the key issue, have you done any diagnostics / checked for fault codes?

**westiej** · 16-04-2011,11:42 AM

Thanks very much for that, not sure how i missed that post! I'll get a valve on order. I've not got access to Vag-Com, if anyone in the London area could spare me 10 minutes to read any codes I'd appreciate it.

**westiej** · 24-04-2011,11:44 AM

OK I'm probably being really stupid here, but I can't work out where the part I need to replace actually is!! A8tech states it's "under the bonnet below the plenith chamber cover near the nsf E box" which points me in the right direction.

I then found a scanned copy of the Technical Service Bulletin, detailing the issue, with a picture of the offending part, but I still can't work out where it is

If anyone can help me track it down I'd be really grateful. My car is a 2.0 TDi, so there's a reasonable amount of space under the bonnet, and I'd have thought I'd be able to see it.

Thanks in advance to anyone that even reads this post.

**westiej** · 24-04-2011,01:51 PM

Actually ignore that last comment, I WAS being really stupid!!

It was staring me in the face. Now lets hope I can stop the AC from blowing super heated air in my face when I wanted cold air!!!

As always, thanks to everyone.

**jc4stuff** · 15-07-2011,05:38 PM

Westiej, did this work for you. Also have you got a link to the Technical Service Bulletin?

cheers, John

**a8 tech** · 15-07-2011,09:26 PM

Originally Posted by westiej

I'v got a '54 plate TDi SE, and there is a very strange fault with the air con. When I turn it on it will blow nice cold, conditioned air from the vents in the centre console, but absolutely boiling hot air from the vents by the doors. This fault seems intermittent, and I'm pretty sure can swap which vents blow hot/cold, or all of them can.
Anyone any idea what might be causing this?

My second problem is that when I switch off the ignition, it isn't always recognised. You can tell as the big clunk you normally hear doesn't happen, radio stays on, and the doors won't work from the remote. This is also intermittent and much worse in warm weather - in fact it doesn't happen in the winter. Will normally behave if I turn the key off and on a few times.

Any help you can give will be greatly appreciated. TIA, John

2nd fault is likely to be the j518 control unit steering column lock, this controls the ignition 15 or the ignition switch as the S contact micro switch fails leaving the radio on and dash lights etc

**RichyS** · 18-07-2011,01:19 PM

Originally Posted by jc4stuff

Westiej, did this work for you. Also have you got a link to the Technical Service Bulletin?

cheers, John

I have this for the TSB: http://audiclub.dk/forum/download/file.php?id=5784

I would be interested in hearing from anyone who has successfully changed the coolant valve. And how much does a new part cost? I found one of the older (not the B revision) ones on eBay for £75 -- which seems a bit of a bargain (it's new).

Need to get my 2.7TDI A6 Avant MOTed soon, so might ask the local Spanner to fit it -- save myself a few grazed knuckles. Not going to bother with Audi, based on passed experience...