[Ethanderall]

I had one of the FOB's for my 2006 325i stolen recently.

The spare key is a 315mhz FOB according to the printing on the rear of the FOB. My question is, do I have to get another 315mhz FOB, or can I use an 868mhz FOB, as the 868mhz items appear to be alot more readily available.

[bmw325i]

You can't get a used keyfob if that's what your trying to do.

[Ethanderall]

No, what I was asking was can 868mhz keys be used as well as 315mhz keys... or, does the CAS module support all the frequency models or just a particular one?

[Dracon]

Originally Posted by Ethanderall

No, what I was asking was can 868mhz keys be used as well as 315mhz keys... or, does the CAS module support all the frequency models or just a particular one?

The CAS only supports the frequency specific to your region. If your car uses 315mhz, then you need 315mhz FOBs.

868 is for the European region, if I remember correctly, 315 is North America and Asia/Pacific regions.

[alpina527]

Originally Posted by bmw325i

You can't get a used keyfob if that's what your trying to do.

Isn't the car coded to the key? ie, a used fob can work with another car if the Cas is coded to the key

[Dracon]

Originally Posted by alpina527

Isn't the car coded to the key? ie, a used fob can work with another car if the Cas is coded to the key

Not with dealership tools. It can be done with special tools (not produced by BMW) to edit the transponder information in the CAS. However, these tools are very expensive (the good ones are 6k-10k).

Normally, every CAS is pre-programmed with 10 transponder codes built in. BMW keeps the transponders, issues 2 in keys when the car is purchased. If you need another key, you order one from BMW, they take the next transponder number in line and put it into a key and send it out. Once all 10 transponders are used, the CAS must be replaced, 10 new transponders are issued and the process repeats again.

[superjay]

I was not aware of that.