LandRange

Does this diversity antenna also have to do with the buttons in the key for central locking? Mine has stopped working, only works some time. I have to put the key in the door, then the central lock works. Its the same with the other key!

losblancos

Has anyone had success cleaning corrosion off of this module? Any tips?

losblancos

So, the answer to this question and OP's question is "yes, perhaps..."

See this post
https://5series.net/forums/e60-discu...6/#post1540577

Lotus99

Good for you! Your theory is not correct for Comfort Access keys though. They have a removable battery inside so don't get charged, unlike non CA keys. Just take out your physical key, and flip off the battery lid to see it. It's the first thing to check in future if your CA is weak.

Make sure to search and look for the tech bulletin on the foam spacers that were added by BMW later on as an update to reduce the chance of water getting in the module, and if you don't have them, get them. Not sure if they're much good though, as mine went bad, even though the foam spacers were there. But it's a cheap added insurance. And silicone the edges of the module case, before closing it.

losblancos

Oh yeah, I meant that only for non-CA keys like mine. I assume for CA fobs the only communication between the key and ignition takes place for VIN authentication if the fob is inserted into the slot. Seems like everything else might go through the diversity module/CA modules (latter if applicable). I'm not an electrical engineer or really all that knowledgeable, just a guess.

Yeah, I saw that bulletin on the foam spacers in your thread, and I also saw that they don't seem to be all that helpful.

I was thinking duct tape/plumbing tape originally, but I assume you're referring to silicon glue or sealant? That seems like it might be worthwhile. I'd be tempted to try sealing the entire black 'box' that surrounds the module.

Lotus99

Sorry, I misunderstood you also. I thought you had CA keys and were saying they get charged in the slot.

I've had my antenna replaced twice actually. Once in early 2012, and then just a year after!

After the first replacement, when it went kaput, is when I opened it up and noticed that the edges of the box with the board inside had even been siliconed the first time, but didn't seem to have helped, and I had foam spacers too.

losblancos

So, just in case anyone's interested or has any input... I set out to do just that yesterday.

Basically even after I cleaned the corrosion off of the diversity module, it kept failing to remote unlock and otherwise sync with the keys, particularly after wet weather. Interestingly enough, all that was typically required to get it working again was unplugging it and plugging it back in. So yesterday I cleaned it again and even took some isopropyl to the connector itself.

Then we cleaned and vacuumed a lot of the dust that gets under the spoiler. The idea was to create a relatively clean area for sealing.

I was debating between silicon sealant and waterproofing tape; ended up using the latter in part because silicon can take a while to cure completely.

The problem that I was worried about, though, was what would happen if the seal from the outside was imperfect (I think it's almost impossible to create an airtight seal around the black 'box' because of the way the wires go in) and some water still got in. Stood to reason that it might take that much longer to dry out. So to that end, here's what we did...

-Cleaned the module circuit board itself with 91% isopropyl and a toothbrush
-Cleaned the connector on the car with isopropyl/toothbrush
-Put the module back in, and before putting the black lid back on dumped a decent quantity of silica gel (a dessicant) into the area surrounding the module. We used something like this cat litter, easily found in a local grocery
-Sealed the lid with this waterproofing tape, which can be found e.g., at wal-mart

I forgot to take a picture of the silica gel-filled module area, but here is the finished product:




We'll see how long this works! I *think* it survived a big rain storm last night; will have to ask my wife about it. I'm somewhat resigned to the reality that I'm going to have to replace this module at some point and probably every now and then thereafter.

losblancos

Well, ^that^ solution only ended up working for about a month or two. But sure enough, the instant I unplugged the module and re-plugged it, it started working again. Which puzzles me, but it may be time to mess about with re-soldering the pads/joints around the plug and adding some solder to make up for any corrosion?

mantraguy

Less than 2 years ago my remote stopped working, so I replaced the diversity antenna module (circuit board). Before I installed the new one, I applied a few thin coats of silicone conformal coating to 'waterproof' the electronics, and I also applied a silicone bead around the rubber seal of the housing. Now I think it's dead again - the remote access still works, but I have no AM or WB radio, and FM is very sporadic (constantly goes in and out of reception, and only on very strong signals - distant stations are not picked up at all). I'm not sure what else to try - the car sees less than 15,000 km/yr and is garage-kept, although we do live in a very wet climate on the west coast.