How the BMW Key is Powered

[jaynana]

Couple of days back some of us were discussing whether the theory that BMW keys get charged in the ignition key hole was an urban myth. found out some details:

Each key contains a wireless electronic chip (transponder chip). The function of the transponder is to receive and transmit data to the EWS II control module. The transponder contains a wireless read/write EEPROM in addition to a small capacitor and coil for self power capabilities.

The functions of the EEPROM are:
• Store codes for key identification, password and changing codes.
• Receive and respond to coded messages from the EWS II control module.

Power for the transponder is produced through the inductive coil and stored in the capacitor. Each time the key is inserted into the ignition AC voltage in the antenna ring induces voltage in the inductive coil.

Ring Antenna
The Ring Antenna is an inductive coil installed around the lock cylinder which provides power for the transponder in the key and the communication link (antenna) between the key and the transmit/receive module.

Rechargeable Battery
The battery inside the key head is charged inductively by the EWS ring antenna via a coil antenna integrated in the key. The charging process is controlled by electronic circuitry integrated in the key.
• The service life of a radio-control key used under normal conditions corresponds to the veh-
icle lifespan.
• If the FZV keys are not used (ie: stored in a drawer), the battery will be discharged after
approx. 1.5 years.
• The time required to fully charge a discharged battery is approx. 30 hours.
• The remote control can be operated about 15 times after a charging period of approx. 30 minutes (driving time)

sources:
http://www.unofficialbmw.com/images/BMW_EWS.pdf

http://www.bmw-club.cz/graphics/manuals ... zkeIII.pdf

[gchristofi]

useful info, thanks. Guess I might just charge my spares up soon.. hope they work after 3 years in a drawer!

[X5Sport]

I think you're advised to use the spares at least once a year to keep them charged and bring the rolling codes up to date. Whether that really makes a dufference though I hae no idea. As long as the battery has not completely died you will be OK though. If I remember rightly, the keys always hold a code that the car will still recognise so that even if they aren't used for a very extended period, all is still well.

We each use our own keys as the seat memory/AC/settings/mirrors etc functions are programmed in. With me being 6'4" and SWMBO being 5'2" (all the best things come in little packages she says) there's a big difference with all the settings!

[jaynana]

[quote=""X5Sport""]

We each use our own keys as the seat memory/AC/settings/mirrors etc functions are programmed in. [/quote]

same thing i want to do but unfortunately i haven't yet found a way of doing it without going to the dealer

see this thread:
viewtopic.php?f=22&t=3133

[pvw10]

same thing i want to do but unfortunately i haven't yet found a way of doing it without going to the dealer

see this thread:
viewtopic.php?f=22&t=3133[/quote]

Me also, stealer says £25.00 then i can view all settings and choose what i wish eg auto locking/beep when locking/individual key actions etc etc but nobody not even BMW HQ can give me a list of what options there are rather than paying £25.00 for a few bits that i may not want and it isnt worth that just for the keys !

My Son is a service advisor at a main dealer and says the only way is bring the car in !!

He says future cars you can programme some things yourself but FYI the cars service history is going in the car, no more books same also for sat nav no more discs :O(

[X5Sport]

I know our E53 and E46 had to be done by the Dealer. Current models have it all built into the iDrive. Probably because so many customers complained!!

This form (Courtesy of those nice folks over on XOutpost) might help...Car Key Memory Form. I used it when I was organising the delivery of mine back in 2005. Not sure if the DRL one applies, but the rest do.

http://www.xoutpost.com/articles/x3/gen ... -form.html

[jaynana]

[quote=""pvw10""]same thing i want to do but unfortunately i haven't yet found a way of doing it without going to the dealer

Me also, stealer says £25.00 then i can view all settings and choose what i wish eg auto locking/beep when locking/individual key actions etc etc but nobody not even BMW HQ can give me a list of what options there are rather than paying £25.00 for a few bits that i may not want and it isnt worth that just for the keys !

[/quote]

do you have the scanner 1.4.0? if you have it you can do all of below with it: auto locking/beep when locking/individual key

[pvw10]

[quote=""jaynana""][quote=""pvw10""]same thing i want to do but unfortunately i haven't yet found a way of doing it without going to the dealer

Me also, stealer says £25.00 then i can view all settings and choose what i wish eg auto locking/beep when locking/individual key actions etc etc but nobody not even BMW HQ can give me a list of what options there are rather than paying £25.00 for a few bits that i may not want and it isnt worth that just for the keys !

[/quote]

do you have the scanner 1.4.0? if you have it you can do all of below with it: auto locking/beep when locking/individual key[/quote]

No i dont, just putting pressue on son for freebie

[jaynana]

[quote=""X5Sport""]I know our E53 and E46 had to be done by the Dealer. Current models have it all built into the iDrive. Probably because so many customers complained!!
[/quote]

on E53s and in that generation of cars its actually done with a device called the MODIC. apparently its a BMW propitiatory piece of kit which is available with dealers. i just can't imagine why they had to make this bit SO complicated!

see below:
http://www.xoutpost.com/articles/x5/gen ... ation.html
http://www.auto-diagnostics.info/bmw_modic

[X5Sport]

[quote=""jaynana""]on E53s and in that generation of cars its actually done with a device called the MODIC. apparently its a BMW propitiatory piece of kit which is available with dealers. i just can't imagine why they had to make this bit SO complicated![/quote]

Coz they knew folks like us would want to play....... .

I wonder what this module does if I pull this le...