Key Fob battery and Diversity Antenna/Amplifier

[Alphaville]

First time owner here... so please bear with me.

Got myself a 2nd hand 2006 523i UK model, recon in 2010. Salesman told me the key fob batteries are weak, need charging. Both fobs can hardly unlock/lock the car, and only works sometimes when I am standing next to the car. After a few days of charging the fob by using the car, it still has not improved. So I started googling and found the following:

1. The rechargeable battery in the fob is the Panasonic VL2020. It is non serviceable, therefore if you want to change, it is a DIY project with replacement battery from ebay.
2. It may not be a battery problem, instead the diversity antenna / amplifier could be failing, or the wiring for the antenna is damaged/loose. Other symptoms for this, besides the remote not working, is the radio reception can get bad.

I am beginning to suspect I have problem number 2 due to a few clues, so my question is where can I send my car (around PJ) for someone to check out the antenna? Don't dare to DIY, the few pictures I saw is a bit daunting cos it involves opening up the C pillar , etc....

Also, if the problem really is the battery, any specialist who can offer their services to have it replaced and reprogrammed?

Thanks in advance....

 

[jarance]

Try this.. Put the key on your cheek and open the door.

This method will increase your range. Trust me, it works but you will look kind of silly sticking the key on your face.

Go to any accesories shop to open the C pillar if you are afraid of breaking the clip.

If you can open the door, no point changing the battery.

 

[moots]

Try this.. Put the key on your cheek and open the door.

This method will increase your range. Trust me, it works but you will look kind of silly sticking the key on your face.

Go to any accesories shop to open the C pillar if you are afraid of breaking the clip.

If you can open the door, no point changing the battery.

he he....uncle J...this works, i tried this on my e39 by putting the key fob on my chin....

alphaville....some good read for you...http://www.bimmerfest.com/forums/showthread.php?t=687477
i would always go for the cheaper solution first.diy the key fob battery change....you tube got video ...

 

[Alphaville]

Update...

The key fob signal seems to be getting better... now I can unlock from 1-2 meters away.
How long does it take to charge the fob batteries? It's definitely taking an awful long time...

Anyone got similar experience?

 

[jarance]

How is your Radio reception? Getting better as well?

Maybe you have bad contact. Try opening the Diversity Amplifier and clean the contact.

 

[Tamaro]

jarance, where is the diversity amplifier and how to clean?

 

[jarance]

Depend on the model, usually at the C-Pillar.

Some later model have the diversity amp hiding in the 3 light area.

 

[moots]

nah.....more info for you...with pics summore

http://5series.net/forums/diy-do-yourself-14/diversity-amplifier-replacement-89011/

 

[Alphaville]

More update....

The FM radio reception is OK, just the remote signal is very weak. It is getting very slightly better everyday, so it must be charging, but very slowly.

Anyway... found the following interesting information....
1. The chargeable key fobs will last the lifetime of the car.
2. It will fully discharge if not used for 18 months.
3. It takes 30 hours to fully charge (in ignition with Accesory or On positions).
4. Each 30 minute charge, they key can be used 15 times (I guess, 15 presses).

Source: http://www.bmwgm5.com/keys.htm

So, since my key fob batteries were really drained, I need to drive around for 30 hours before it is fully charged!

 

[jarance]

I heard that some people charge their key using the toothbrush charger.. I have not done it myself and it could be a myth..

see below:-

https://www.youtube.com/watch?v=kC68Z7CP2XM

https://www.youtube.com/watch?v=kC68Z7CP2XM

 

[moots]

More update....

The FM radio reception is OK, just the remote signal is very weak. It is getting very slightly better everyday, so it must be charging, but very slowly.

Anyway... found the following interesting information....
1. The chargeable key fobs will last the lifetime of the car.
2. It will fully discharge if not used for 18 months.
3. It takes 30 hours to fully charge (in ignition with Accesory or On positions).
4. Each 30 minute charge, they key can be used 15 times (I guess, 15 presses).

Source: http://www.bmwgm5.com/keys.htm

So, since my key fob batteries were really drained, I need to drive around for 30 hours before it is fully charged!

wah....good info...looks like we shall have to alternate the spare keys to be used every once a year....

I heard that some people charge their key using the toothbrush charger.. I have not done it myself and it could be a myth..

see below:-

https://www.youtube.com/watch?v=kC68Z7CP2XM

https://www.youtube.com/watch?v=kC68Z7CP2XM

uncle J....really aaar....nanti battery kong and data also kong and key not recognised by the car how?
errr.....you try dulu and let us know ya......tq

 

[Alphaville]

Update...

I ordered ML2020/VL2020 batteries from ebay (from Germany). Opened up my spare key (use knife), unsoldered the original battery, soldered the new battery.... but... no difference... still the same. Checked both batteries (old and new)... same voltage and current.... so must be the key fob has gone kaput (also the lock button does not work).

Have not tried changing the battery for the main key fob. Rather I'm thinking of buying a replacement key (those with replaceable batteries).

Anyone know where to get and how much? Trying to avoid going to AB or Ingress... don't think it will be cheap.

Thanks.

 

[Alphaville]

Update... problem fixed... well... almost..

I ordered diversity amplifier antenna from Ingress, cost me Rm850+. Replaced it and now the remote works from 5 meters away. Have not fully tested what is max range.

The FM reception seems to be the same, more sensitive now, need more testing....

However, 2nd key fob still cannot unlock. It can lock and wind up window, open boot... but the lock button has no response. So, confirm the key is busted.

In summary, if you have problems with the remote, following is the step by step procedure:
1. Change batteries - order ML2020 (not VL2020, the legs do not fit) from eBay, very cheap, Rm18 each. Cut open the key fob casing (case destroyed), unsolder the old battery and solder in the new battery. No need programming or anything like that.
2. Clean diversity amplifier contacts - open up, take out and sand paper the contacts and clean with alcohol (here's a guide: http://www.bimmerfest.com/forums/showthread.php?t=442784&page=2)
3. Replace diversity amplifier - order from AB or Ingress, make sure you get the right replacement part, most probably your current one part number no longer available. Check realoem or bmwfans.
4. If you destroyed your key fob casing from step 1, you can buy replacement from eBay, around Rm36 each.

Good luck!