A6 aircon blowing hot and cold

Jun 25, 2009 14 Replies

I have a friend with a 3 year old Audi A6 (2.7 diesel I think) that has had a problem for a long time now with the aircon intermitantly going a bit haywire and either blowing very hot or very cold.



Garage is at a loss as nothing shows up in the computer logs (and I guess intellegent guesswork/diagnosis is beyond them) and because the problem is only intermittant and typically never happens when it's taken to the dealer.



Are there any common known problems with this car's aircon?



TIA



Tim



If it's random then you'll want to plug it into Vag-com & see what's going on, normally it's a sticky flap or motor but interrogating it's a lot easier than removing the dash.

Garage have already done that, hence the reason I said "nothing shows up in the computer logs".

Tim

They said they'd already done that on my friends Polo, it still had all the faults visible when I plugged the laptop into it.

Find another garage then...!

Seriously, if it is blowing hot, and yet selected cold, it is quite easy to see in the live data, what actuator or sensor is feeding back the wrong info to the climate etc.

Tim.

Yeah but, you say "live data". This problem is intermittant and never happens when it's taken to the garage (as is the way with these things).

Tim

While not exactly the cheap option, (but no more than an hours labour at a main dealer) I've heard good reports on these;

formatting link
plug it into your OBD socket and it records all error codes over 24hours, then plug it into your USB on the PC to view the record. I'm just waiting for a dodgy intermittant problem so I have an excuse to buy one ;)

Now that looks interesting. Just the sort of diagnostic tool a main dealer ought to have for these intermittant problems.

Any idea if it can be left running for more than 24hrs and then unplugged after the problem shows itself? I'm guessing it would hold the most recent data and ditch the data >24hrs old.

Tim

I'm not sure, I'd imagine that if it could record more than 24 hours, it'd say so in the sales blurb. It's true though, it'd be perfect for main dealers to hand over to their customers who have intermittant problems...

I doubt that it would rcord aircon faults though, as they won't register on generic OBD-II.

Oh bugger, it was a cracking idea while it lasted though ;(

Although the aircon module records them. For some reasoin most VW/Audi dealers seem unable to retrieve them though (& if they're Marshalls they couldn't even be bothered to clear them whilst claiming they'd found no record of them). As per all discussions of this nature on VW/ Audi/Skoda/Seat you want to plug it into VAG-Com yourself which will record flap sticking or motor fault if you're getting random temperatures.

Alas, not my car and the software is pretty expensive.

Tim

You could post on one of the VAG Forums and ask someone. Most have a member map for owners of VAG-COM.

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