[muffking]

Below is a brief tutorial on how to remove the E91 Antenna Diversity module which corrodes through getting wet, causing radio reception and/or remote central locking problems.

1. Open the glass window and pop off the 5 plastic screw covers with a small flat screwdriver.
2. Where the 5 covers were are two T20 Torx screws, remove them.
Two grey/white clips, use thin pliers to pull the centre pins out and to remove the clips.
The centre hole just has a 10mm nut which can be removed with a 10mm socket on the end of a bar.
[pic 1]

3. Close the glass window as the spoiler will now be loose.
4. Pull the spoiler down and then lift it away from the window.
5. Only the brake light wire from the spoiler and the water pipe for the rear window washer jet will keep the spoiler attached.
6. Remove the T20 Torx screws from the cover where the wires go in to, this will reveal the Diversity module.
[pic 2]

7. Below is a picture of the Diversity module that controls the radio antenna.
It should have numbers such as 6520-6934846-06.
8. To remove it simply unplug all connectors and unscrew the two 8mm nuts.
[pic 3]

9. Dry the whole thing out, try to remove the corrosion (perhaps with a dry toothbrush) and hope it works. Failing that, a replacement will cost around £200 from a main dealer.

n.b. When refitting a new one, run a bead of silocone around the top cover to seal it from the rain next time as BMW didn't seem to have done a good job sealing the ones on the E91 & E61.

[raddersmanu]

Have now removed spoiler to look at diversity module with a view to getting the part number and passing onto a helpfull spares dealer on ebay trying to match one close on specification but I was rather dissapointed to find no signs of water contamination at all it looks as clean as when it left the factory? So now Iam wondering if it is the amplifier at all causing my central locking not to work what else could it be ? any suggestions.
The central locking works off the dash button and when the emergency key is used, I only have one remote so can not try another.

[kowalski]

last week same thing happened to my car with only difference that after it was left standing for over 24 hours it started working again but just for a few days as it has stopped working again. Did you find out what the problem was with your car?

[muffking]

Yep, corrosion on the circuit board. After the snow had melted you'll probably find that it's drowning in water and is on borrowed time. It may be time to get the hairdryer in there quick.

[kowalski]

thanks - I had a go but stopped when I realised that pulling the screw covers off requires more force than the amount I felt comfortable applying. thanx for the advise re the hairdryer but I'd rather do it properly - spoiler off - so I'll take it to a garage this afternoon.

[kowalski]

Been to the garage but they can't tell without taking the spoiler off whether it's water damage or damaged wires (apparently a common fault on tourings).

However, removing the rubber wire cover from the glass panel revealed a bit of corrosion and I now have the car booked to sort that and investigate next week.

As the corrosion seems to have been there for a while with no visible signs it is probably a good idea for other touring owners to investigate theirs as well.

[kowalski]

As it turned out there was no visible corrosion damage to the module and no split wires were found. The module simply died... Had it changed by the garage and everything is working again.

[muffking]

Glad to hear it. Damaged wires is less common than a faulty diversity unit, but the usual signs are water in the module housing. Either way im glad you found it.

[bigboytom21]

hi i need to do this but cannot open the rear window to get at the last rubber plugs because its broken

any ideas would be appreciated greatly !!

[muffking]

Youre jiggered unless you can remove the window trim on the inside and drill holes that line up with the screws?
My advice though would be to see if its possible to gain access to the lower tailgate panel between the tail lights and see if you can unlatch the glass door.

[AndrewAB]

bigboytom21 - you could try the glass opening switch/handle on the glass panel. I levered off the plastic top cover with a blade and inside is a foam pad with the switch contacts underneath on a ribbon cable. I tried squeezing then used the pressure of a blunt blade across the contacts inside the foam to get the glass to pop. I had to persevere for ages to get it to open. This may only work for a faulty switch, not sure.

[AndrewAB]

PS: Re. my post above. Remember the tailgate glass switch only operates with the car fully unlocked.

[Captsi]

My remote stopped working after a period of rain but then a few days later started to work. Then it rained again and it stopped working one more time. Following these instructions saved me a pretty packet.

On opening up the spoiler it all seemed dry and on opening the waterproofed case it all seemed normal, so I wasn't sure what the problem was. Was it a) the diversity filter, b) the wiring loom or c) another electrical fault.

I hedged my bets and bought a salvaged diversity filter from eBay for about £110 (I figured I could probably resell it for a small loss if that wasn't the issue) and immediately the remote locking worked once again. Phew.

There are whole boot doors available on eBay as well as from various salvage yards around the UK, there are also the occasional diversity filter available too. Alternatively you can buy a new one from BMW for about £255 part only.

This little guide was great at helping get to the bottom of he problem, so thank you.

[swappyd]

I’ve got the issue where the key buttons don’t work!
I’ve checked all the fuses, wiring and finally changed the diversity module!
That didn’t work so reset software and still nothing!

Has anybody got any other ideas!
I’m at a lose what else to check!

[muffking]

Originally Posted by swappyd

I’ve got the issue where the key buttons don’t work!
I’ve checked all the fuses, wiring and finally changed the diversity module!
That didn’t work so reset software and still nothing!

Has anybody got any other ideas!
I’m at a lose what else to check!

Did it used to work ok or is the car new to you?
Do you have a spare key fob and is it the same problem?

[MightyMouseTech]

Originally Posted by swappyd

I've got the issue where the key buttons don't work!
I've checked all the fuses, wiring and finally changed the diversity module!
That didn't work so reset software and still nothing!

Has anybody got any other ideas!
I'm at a lose what else to check!

Most likely broken wiring on the passenger side harness inside the flexible boot in between the body and tailgate. Happens all the time. A real PITA to fix.

[swappyd]

It worked fine in the morning locked car then nothing!
The wiring on the drivers side and that was ok!

Ok I’ll have to take it apart to check!

[KASHe91]

Originally Posted by MightyMouseTech

Most likely broken wiring on the passenger side harness inside the flexible boot in between the body and tailgate. Happens all the time. A real PITA to fix.

Originally Posted by MightyMouseTech

Most likely broken wiring on the passenger side harness inside the flexible boot in between the body and tailgate. Happens all the time. A real PITA to fix.

Would a weak/broken wire also be the case if I have to put the key against the antenna itself for the car to open? As I can open/lock the car but the range is super limited.
I've changed keyfob battery as have comfort access keyfob.

Ps first time posting a comment so working out how to use this forum

[brbsqskp]

thanks, I'll try to do something like this sometime

[juni0r123]

I've got problems with the wiring or possibly the diversity antenna, but I can't for the life of me work out how to remove the spoiler, mine isn't like the one in the picture, it looks like this one & I can only see 3 covers, removing them & the nuts & screws doesn't seem to be enough, anyone any ideas?

[DDkev]

Originally Posted by juni0r123

I've got problems with the wiring or possibly the diversity antenna, but I can't for the life of me work out how to remove the spoiler, mine isn't like the one in the picture, it looks like this one & I can only see 3 covers, removing them & the nuts & screws doesn't seem to be enough, anyone any ideas?

The glass booth has 2 more plastic things that hold on them if you open the lid you may have a nut holding itt also or it might be that my cars previous owner had done somthing to it

[winnibago]

Thanks OP (muffking) & others for creating and contributing to this thread. The resources provided in this thread created a decade ago ended up being the fix for my issue!

For posterity: I have a 2006 e91 w/ 90K miles and the (non-comfort access) key worked for ignition, but the remote key function wasn't working for lock/unlock. The wiring bundle in the flex conduit of the hatch (which is typically the culprit) was tired looking, but not the cause in my instance.

Ultimately, the replacement of the antenna diversity module (same part) from an e70 resolved it for $50 (eBay) and 30min of DIY labor.

Thanks again fellow wagon owners!