i have a 2001 530d and have a serious problem.
i turn the ignition off and have notice the climate control turns on blows air for a short burst and keeps repeating this. there is no display or lights on the unit when ignition is off and keys are out. it starts off with a faint humming sound. my car did not start yesterday. battery was flat. not sure if it this that called the problem.
happened yesterday. had to jump start the car. stopped happening all day today and has now come back. not sure if that was why the battery ran flat.
has anyone had this problem before? please help!
do i need to change the unit.

i have a 2001 530d and have a serious problem.
i turn the ignition off and have notice the climate control turns on blows air for a short burst and keeps repeating this. there is no display or lights on the unit when ignition is off and keys are out. it starts off with a faint humming sound. my car did not start yesterday. battery was flat. not sure if it this that called the problem.
happened yesterday. had to jump start the car. stopped happening all day today and has now come back. not sure if that was why the battery ran flat.
has anyone had this problem before? please help!
do i need to change the unit.
Sounds like the Final Stage Unit. Do a search on Final Stage Unit and you will see MANY how-to's. I had the same problem, but it was blowing full blast all the time and I had to jump my car as well. Just unplug it until you get your part in, then change it yourself. Part runs about $70 at bavauto.com or any other online parts store, but about $100 at the stealer (at least around here) and they will charge you about $300 if they put it in. It takes all of about 5 minutes and no tools to change, just hope you don't get a defective one when you buy it like I did.:rolleyes

just hope you don't get a defective one when you buy it like I did.:rolleyes
Wow! That's some bad luck!

Believe it takes more than 5 minutes to replace...more like 15-20 min ;)

Took me about 30 mins. Getting that old sucker out and unplugging the harness was a pain. The next one will take half the time, although I hope I don't ever have to do it again.

glad to hear i'm not the only one suffering out there. how can i be certain its the final stage unit not the cllimate control box?
my a/c does not blow cold air as well. i thought this was because of the gas on empty. have not had a chance to find out yet.
the heater humms sometimes as well. especially when on full power. i changed the pollen filters which made a difference but u can still hear it when on full blast. is this all part of the symtoms ??

I don't know how to certain that the FSU is a problem. There is no cosistent failure pattern. Most people just swap it out because it's relatively cheap. Realoem lists the price of the control box at about $600. So if you're going to throw parts at the problem, it's wise to start with the cheapest part that is likely the problem.

thanx i shall give it a try. would cleaning the so called small fan behind the control box make any difference? i never knew there was a small fan that stayed on for a short period until i started researching this sight. just cant find anything more on the topic!!