BCM module water damage, where is the leak coming from?

[khawari]

So I'm trying to replace my body control module and I noticed that there was a lot of water damage on the actual unit itself. There are droplets of water that were sipping from the cables themselves and it got me thinking that perhaps I need to go find this leaking problem, fix it, and then replace the BCM. A user that I was talking to on this form suggested that I go find the brake booster drain, or the drain that's near the brake booster and empty that. I don't know where to find that for my car, any ideas? It's for the Audi A4 B6 and online videos are kind of conflicting and not really giving any very good information as to what exactly I should be looking for.

Sent from my ONEPLUS A6010 using Audizine mobile app

[egovreau]

The brake booster is on the firewall in front of the brake pedal on the engine side. There will also be a large black box next to it which contains the ECU. Usually it will collect leaves and dirt and clig the drain. When that happens it fills up and spills back into the cabin. Using pressurized air will normally clear it out.

The other possibility is your sunroof drains (if you have one). You can open your sunroof and slowly pour water into track. There are four drains, each on a corner. The front drains empty out at the front door jamb outside the cabin. The rear drains empty out under the rear fender wells.

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[EuroxS4]

I put my money of Either Cracked ebox cover cause everyone always forgets about that one screw or think there isnt one there. Hood cable grommet or windshield leak if it was improperly installed. Those are the most common causes of water intrusion into the vehicle. Unless you have a sunroof and its got a blocked drain hose or a hose thats not hooked up or separated.

[khawari]

I put my money of Either Cracked ebox cover cause everyone always forgets about that one screw or think there isnt one there. Hood cable grommet or windshield leak if it was improperly installed. Those are the most common causes of water intrusion into the vehicle. Unless you have a sunroof and its got a blocked drain hose or a hose thats not hooked up or separated.

It was a cracked ecu box! Well, cracked in a corner where a screw is located. Car is chipped etc so somehow that thing broke from savage hands not belonging to me! I never noticed it was even cracked there, and water seeped down into the car onto the BCM after a car wash last week. But it's been like this for a loooooooong time..... So why now lol

Problem fixed though now.

New bcm didn't need coding which was odd but... Mechanic friend of mine told me that the car would not start or should give an obd2 reader code error that would make it obvious that I need to code. So far, no problems and my security seems to work, I see the red lights that flash when locked!

Sent from my ONEPLUS A6010 using Audizine mobile app

[DontStopmeNow11]

In general, you should solve this problem as soon as possible, and preferably contact a good dealership that knows how to work and solve your problem, because I once left my car in the garage in the same condition. I had to contact water damage restoration service -- https://www.lawtoncr.com/water-damag...damage-repair/. After all, when I came home, my entire garage flooded. So I hope my post will be useful and you will understand how serious your problem is and why you should not solve it yourself.