spediegunz

Im hoping for some opinions from those who have been through this before. My remote is so bad now, that I can be standing right next to the car and the buttons still wont work. Only after a few tries it will respond, today i found myself looking like an idiot putting my key under my chin.

any way after some research it seems changing the diversity amplifier/antenna behind the 3 brake light seems to be the common fix. I was just wondering before i troll into bmw to get it replaced, should i try to change out the battery in the key? in my mind if the key gets recharged by the car maybe its pointless but I'm also thinking if the battery is no good its not holding the charge anymore and therefore the reception is very weak? any thoughts i figure it would be a good time to change it because i plan on doing the diamond key to switch blade key fob mod



so should i even bother with the battery or just make my appointment at the stealership for the diversity swap?

pcy

I had the same problem - key doesn't work from distance. I bought a new key from BMW since I didn't want to mess with replacing the battery in the fob. New key didn't solve the problem. I thought the diversity amp fins/connectors may be oxidized or not making good connection; I removed the diversity amp and all the fins were in perfect condition and they were making good contact. So, amp must've been failing.
So, I bought a new diversity amp on-line for $222 including shipping. It took me about 30 minutes to replace the amp.

I recommend you buy the diversity amp online and replace it yourself. Search for DIY instructions. I'd bet dealer will charge at least $600 for replacing (part+labor) diversity amp.

spediegunz

i saw the diy i consider myself handy and i have taken my door panels off before and my dash and center console apart so maybe changing the diversity amp might be something i can handle, did you improvement when i switched the amp ? also Im wondering why could there be corrosion or oxidation is it because of sunroof leak?

pcy

Diversity amp replacement solved my problem. Now my key (old key as well as new key) works from far end of the parking lot in the mall.

As for the oxidation of the contacts, I didn't know whether there was anything wrong with the contacts [on the old diversity amp] or not. Another member had a similar problem and he stated that his diversity amp started working after he cleaned the contacts. So, I thought I could check it out and see if the contacts are clean and making good contact. Yes, sunroof drain leak can cause corrosion on the contacts.

If your car's rear seat can fold down, that will help (you can sit on the folded seat and 'look in to' the roof liner after removing the C-pillar cover.

Bobbadio

I'm experiencing the same thing with my 550. Does it come down to the point where the key won't work at all? Or is it more of just a nuisance?

spediegunz

Well I've never gotten to a point where I couldn't lock or get into my car but its just so annoying not to mention embarrassing when you drive a "BMW" and regular things start acting up. I took pcy advise and ordered a new diversity amp I found it cheapest for about 230 crossing my fingers that install goes smoothly and it solves my issues. Heck I know people with viper alarms that can lock/unlock from like 5 blocks away......, smh ill keep you posted

Bobbadio

Looks like one more thing I am going to have to add to my list of things to do! Yes, please keep us posted! Goodluck.

Shlooky

Put the key up to your head then try to unlock LOL.

ldesouza

Also have this issue! Not to the point where it doesnt work at all, but the range is only a few feet. Keep us posted!

spediegunz

I'm gonna send the video to mythbusters so they can crack this case open