ECON button stays lit and no A/C
 

I posted this in the wrong section but I hope the fellow B6 audi members can help.

I just bought my used 2004 Audi A4 3.0Q a month ago and today was the first hot day here in Mass.

For some reason my ECON is always lit and I can't get AC.

I read on other forums that it could be numerous stuff..but how should I approach this?

Some people said to check the fuse...then try recharging the AC..but if the ECON button is on, the compressor wont be on..so how would it take the recharge?

Help.

- Alex

It is all too familiar:

https://www.audiforums.com/forum/sho...d.php?t=126893

Thanks Dan

UPDATE

I havent fixed the issue yet becuz I havent had time...but here is something interesting


in the morning..when its cold...I can put the climate control on "LOW" and the ECON buttons stays off....but still...no AC

drove to work...got out at 5pm and it was warmer outside..guess what, put it on "LOW" and ECON light stays on...

around 9pm...it was cold outside again...and guess what...put on "LOW" and ECON buttons stays off!!!....

based on this..could I just be low on refrigerant???

how could u tell when the AC Compressor is operating even if its low on refrigerant?

If you check the valves when you're trying to top it off it should read the pressure, make sure it has enough in there.

theres two valves....do you know which one I attach the gauge too? or does the refrigerant gauge will only fit on one of them?

It should only fit one, but again I never worked with AC. Does the bottle come with instructions? If you're missing only refrigerant then it would be a cheap fix.

You can't diagnose an A/C system by just reading the low pressure port (which is the only one you can access) you need to see both the high side and low side with a set of manifold gauges. I don't recommend buying a set of gauges and doing it yourself, not to mention its illegal in all 50 states for you to do so. The system is also hard to diagnose even with a set of gauges, you need to know what you're doing. You CAN however check the A/C control head for fault codes using a vag com, when the ECON button stays lit there is a fault code stored in the control unit.

is that some accessible thru autozone or do I have to buy the diagnosis electronic myself?

No, a vag com is a software you can download to your laptop for free. You just need to buy the cable. Its basically a reversed engineered version of the dealers VAS scan tools, its basically a $5,000 scanner that you get for free, its a nice perk to owning any VW product. www.ross-tech.com. You can also buy the cable from them for about $400, you can find cables on Ebay for cheap but........they don't always work.