stevep69

I searched the forums pretty extensively and did not see any relevant threads but forgive me if this subject has been brought up already. I have an 04 S4 that seems to shoot out only hot air of the vents unless I change the temp to low. Any ideas what could be the issue? I took it to an Audi shop in town and they thought it was the A/C control unit as everything else checked out fine. They were hesitant to hook it up to a new unit as it would cost them $1200 if they used a new unit and it was not the issue. They recommended taking it to the Carrousel Audi in Golden Valley, MN for them to take a look at it. I am just curious if anyone else has had the same or a similar issue and what it took to fix in terms of the steps and cost. Thanks.

nitro1

Yup...this is a common problem. They will try and say its nothing, then they will say its a small leak (and charge you to refill the freon each time they try and figure out the problem). When its all said and done, my money is on the compressor needing to be replaced.

mredd6

Audi S4 B6 4.2L - AC not blowing cold air - the only cdc code is 01336 which says control unit is operating in simplex mode. Replaced pressure sensor. Freon shows at correct pressure. Compressor is not kicking in. Is there a way to force the ECU to kick in the compressor using the VAG unit or other alternative to see if the compressor is bad? Other than changing the compressor, what should I do next?