losblancos

Update: Fixed. See post 5 below.


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Hey all,

First time poster; wife and I just bought an '06 530xiT. Love it so far, but there are a few small issues that need sorting out, the most annoying of which is our apparently dead keys!

The car has the newer style fobs with push button start like my E90's of the same year; not the traditional diamond key (which I prefer!). The car does not have comfort access.

I've done a ton of reading and research on this in order to narrow things down. I *think* it's the remote batteries, but here are my data points and why I'm a bit unsure:

-Neither remote works to lock/unlock. The car is an '06 so I know it's possible that both remotes' rechargeable batteries have died (non-Comfort Access), but it just seems unlikely. My E90 of the same year and fob style has more mileage and both of my remotes are working just fine. My spare was probably used less than 10 times since I bought the car so it's rarely ever been recharged and it's working just fine with great range.

-I don't know if this is typical behavior, but iDrive doesn't seem to 'remember' what I was doing last - i.e., even if I was listening to a CD before the car is turned off or if the radio was on mute, the car defaults right back to the first radio preset 91.5 with volume on.

-Similarly, the car does not seem to remember settings for longer than a brief period of time. Last night I tried setting FM preset 2 to 94.1 and the diamond button on the steering wheel to mute the radio. This morning, my wife told me the diamond button was changing air recirculation and preset 2 is now 93.9. (That said, I was able to save seat memories.)

-I didn't connect the dots before, but both my wife and I have noticed that while the FM radio works just fine, its reception isn't quite what I'd expect it to be - it definitely fades in and out more than my car [E90] does.

I suspect with a little more trouble shooting and some help I should be able to figure out pretty quickly if something is amiss with the keys or diversity antenna/amp (or both!).

Before buying replacement batteries and baking/hacking the fobs open to try soldering a new battery on, I was wondering if anyone has any suggestions for testing the key batteries and confirming that's the issue

Thanks!

pcy

Do the remote keys work if you use them INSIDE the car [or very close to the rear window]?
Does your car has [metallic] tinted windows?

One of the typical symptom of diversity amp failure is the range of the remote keys is shortened significantly.
Do the remotes work if you put the keys right next to rear window and press buttons?

losblancos

Nope, car doesn't have any tinting, and I tried using the remotes both inside the car and immediately next to the spoiler - no dice.

I think the loss of iDrive settings is highly suggestive of something up with the keys themselves (and I tried this again yesterday - the car won't save radio presets or other user profile settings for more than ~10 minutes. Set a preset, turn the car off, come back 10 minutes later and it defaults right back to 91.5).

That said, I might pull the diversity antenna/amp today just to make sure it's not the culprit. I can't readily account for how it would have something to do with the iDrive settings getting lost, but maybe something like this:

-Car's battery was changed and/or car somehow loses synchronization with the remotes
-Amp is also faulty, hence why I can't get the remotes to resync with the car; iDrive can't find the remotes as a result]

I would just try changing the remote batteries but I want to be absolutely sure to the extent that's possible that they're the culprit before I hack them apart (or send them off to bmwgm5 or someone else to fix them).

losblancos

This is what my diversity module looks like:



Obviously I'm not thrilled that I'm probably going to have to drop $300 on a part without even knowing if it's going to fix the problem.

losblancos

FIXED!!!

Thinking I have little if anything to lose, I went out and bought a bottle of 91% isopropyl alcohol and a dollar store cheap nylon toothbrush. Cleaned the visibly corroded parts of the board and let it dry for about an hour (probably not needed).

This is what it looked like afterwards:



Reinstalled the module, grabbed both keys, wife and I held our breath... and it worked! As a matter of fact, the module seems to work flawlessly; iDrive now seems to remember each key's individual settings and the remotes work from a good 50ft+ away. My theory is that the ignition slot itself only charges and authenticates the key; seems like the rest of the communication between the car and key goes through the diversity antenna or is at least reliant on it somehow.

Can't believe it was that simple! Now to figure out the best way to make sure this doesn't happen again. Thinking some combination of foam inserts/duct tape/plumbing tape?

Redtwin

I would be more interested in finding out how water got to it rather than keeping water out of it.

losblancos

It's a fairly common problem, and if you take it apart like I did yesterday it's very easy to see that BMW did a fairly poor job of protecting this part from the elements - it's difficult to imagine how water wouldn't get into the diversity module.



^This is an E91, but same location and the module itself really is not very well sealed.

(note my car is an E61 touring, not an E60 sedan)

pcy

losblancos, good for you!! You fixed the problem.
Once the rust starts, no matter how much cleaning you do, the rust will continue. So, my guess is that the problem will come back. If the problem comes back, you know what to do...

Redtwin

That would explain it, the E60 has it on the inside of the roof.

mladen5

Just a quick note that i had an issue where my remote keys would only work when approx 2 foot from the spoiler. Removed the diversity amplifier, looks like a small amount of water ingress had got to it at spme point, didnt look like much to be fair. Gave it all a clean with electrical contact cleaner and a toothbrush, quick blow on cold with the hair dryer, and plugged it all back together. And voila! It now works perfectly. Wrapped the casing in cling film to prevent any further water ingress. Massive thanks for the advice, was very quick and easy to do and potentially saved me a small fortune. Thanks!