I have a 2000 E39 528i. I bought a 08 535i for my wife and the E39 has been sitting for a while. I have been starting it occasionally to keep the battery up. I decided to sell it and went to start it up and clean it up from sitting so long. The air bag light is on and the remote locks don't work with either key. I started it up to take it for a drive and heard water sloshing around. I found water standing in the rear floor a couple inches deep. I am baffled at where the water is coming from and I suspect the air bag module (crash sensor) might have got wet from the water. I also found water in the trunk under the spare tire.
I am wondering if anyone has had problems with the remote locks not working and what the solution was? I can't unlock the doors or the trunk with the remotes. I had to replace the module in the passenger door a bit back because the windows would not go up and down. Everything worked very well a few months ago when the car was last used.
As for the water, I have new weather strips that go around the front and rear windshields, they were falling apart. But the rubber that is deteriorated should not cause a water leak. The windshields should have their own seals. The weather strips are also falling apart on my 08 535i, and naturally, it is just out of warranty. If anyone has any information on any of this I would appreciate knowing the solution.

The water entry was an issue with E39 and E46 and i think it's also on the E60 but they may be different issues.
This module you had to replace for windows was a window regulator? If so that's not really a module, There's no modules in the doors. Window regulators are a common failure item on both E46 and E39.

I suspect it was raining hard? I'd be very interested to know. It was raining like crazy here and I found water in my wife's E46 in the passenger foot area but it wasn't really bad. I just damped it with a towel and used a dry-vac to suck out any moisture then left the doors open in the garage for a night. I can't rip the car apart just yet to inspect where it came from though.

I assume the airbag light is from the connectors. I would disco the battery and leave disco'd for a while and make sure the car is dry. May require you to pull up carpet

You say the E39 had a water entry issue. Where did you get the information and do you know where it typically entered the car from? I found 6 inches of water in the spare tire well and about 2 inches in the rear floor on the drivers side. I can't see any evidence of water entering anywhere. I am wondering if it might be coming from around the sunroof with possibly a stopped up drain line? I have the car sold as soon as I can take care of this problem. I won't sell it as long as the problem exists.

OK, I have found that water leakage in the doors of the E39 is quite common. Today I checked all 4 doors and found three of them leaking. It is no wonder that the carpet got wet. It not only got wet but had a good 3-4 inches in the rear floor board and possible 6-8 inches in the trunk spare tire well. After getting the leaks stopped I will have to remove the carpet, clean and dry it. It has been a while since I removed the console from a BMW but I don't see any way around it.

Ed

Water comes in from bad door seals. I guess it can happen on any car but what I mean is that I have read a lot of E39 owners and E46 owners having this issue. I have an E39 and E46 and I've never had this issue so no telling if it's a maintenance issue that isn't taking care of.

I wouldn't sell this car to anyone unless you're replacing the carpet. You have only 48-72 hours to dry the carpet. Check all wires and the electronics as well.

When I can get around to it I will remove the carpet and clean and reinstall it. The leak was not caused by poor maintenance. Underneath the door panels there is a water barrier that is held in place by a rubberized sticky seal that is installed by the factory. Apparently, as the sealant ages, it can come loose and let water that enters around the bottom of the door glass run down inside the door and into the cab of the vehicle. By opening the door and letting a water hose gently run down the glass, you can look at the bottom of the door and see the water run out. If this seal leaks, it will run out around the bottom of the inside door panel and right onto the carpet, flooding the vehicle. It seems that the rear doors are more suspect to leak. I hadn't driven the car for several months and when I started down the road I heard splashing. There was three to four inches of water in the rear floor behind the drivers seat. Once it gets that wet the only alternative is to remove the carpet to dry. There is no possible way it could ever dry without removal, it could stay wet for 20 years and stick to high heaven.

I Am Agreed With You AchtungE60.I Am Using E46 Last Three Years But I Have Not Faced This Problem Before.