Comfort Access Issue (new keys)

[Johnnyj525]

Hey Forum!
So i recently bought an e92 m3 from someone who bought it form an auction. Long story short, the car was left in an airport parking lot due to the owner fleeing the country. The car did not come with original keys and a new transponder and key were mated to the car.

The key and remote work fine for opening, closing, starting the car but my comfort access does not work. Is this something i can code?
Can anyone advise? Thanks in advance.

[roastbeef]

Not all cars have comfort access. Double check using a vin decoder.

[Johnnyj525]

I checked and indeed have CA. also have the ridges on my doors.

[Dpc2u]

Well, it needs to be a comfort access specific fob for one thing. Easiest way to tell is does it have a battery. Non C/A ones don't as I recall. They charge in the ignition. Also, even if it is a C/A fob, the car only allows 2 fobs at a time to use C/A, so a dealer or a coder would have to reprogram the C/A to accept the key.

[Dpc2u]

Here is a link to the coding topic. https://www.e90post.com/forums/showthread.php?t=1285135

[M43S7RO]

Fob for CA has to be programmed to the car in order for it to work. Its not as simple as buying a CA fob for a CA equipped car.

My dealer charges north of $100 to program, not sure if it can be programmed outside of a dealer.

[Johnnyj525]

thanks all, does anyone have a link for CA keys?

[Dpc2u]

Not that easy. Sure you get a cheap knockoff or used, but I have not heard of folks having good results. Reality is, you are probably looking at $350-$500 with programming and coding. Dealer, or a BMW Indy with the right equipment. Most locksmiths won't mess with CA. There are some online options, but very pricey. Good luck, I love my CA and would hate to go without.

[GRUESOM3]

Originally Posted by Dpc2u

Well, it needs to be a comfort access specific fob for one thing. Easiest way to tell is does it have a battery. Non C/A ones don't as I recall. They charge in the ignition. Also, even if it is a C/A fob, the car only allows 2 fobs at a time to use C/A, so a dealer or a coder would have to reprogram the C/A to accept the key.

I have 3 keys for my 08 e90 m3 and they all work for comfort access

[Dpc2u]

Originally Posted by GRUESOM3

I have 3 keys for my 08 e90 m3 and they all work for comfort access

Learn something new every day! Good to know.

[pjk380]

I picked up an extra C/A fob from a reputable bmw indy. I ended up having an issue with it and had it replaced. Its not worth going the cheap route for C/A. If I had to do it again, I'd bite the bullet and go thru the dealer.

Good info here about C/A -https://www.m3post.com/forums/showthread.php?t=1522913

[deansbimmer]

Originally Posted by Dpc2u

Also, even if it is a C/A fob, the car only allows 2 fobs at a time to use C/A, so a dealer or a coder would have to reprogram the C/A to accept the key.

This is correct. We assume OP has the CA option and has purchased CA keys. Good.

To remedy this you need to disable the two original key numbers from the CAS via ISTA-D, and that will let the new keys take their place. There are only a limited number of transponder ID's programmed into the CAS system from the factory. Replacement keys are simply new key fobs programmed with those matching ID's. The original transponder numbers are stored and kept by BMW. Consequently if you have replaced your CAS or DME with used units those numbers kept by BMW won't be relevant anymore.

It is only possible to have two unique ID comfort access keys working at one time. It is possible to clone either of those keys via third party software which will allow more than two physical keys to function with CA.

It is also very difficult to find locksmiths who are able to work with our CAS4 system due to these factors and others. It is generally a BMW specialist's offering. To generate a key you have to know the stored transponder ID's which are encrypted into the CAS. You have to have special equipment to pull those down. And then you have to have the software to enable the CA function. If you have an existing key then it is easier to have a locksmith clone it, but still there are few locksmiths who can even do that.

[Johnnyj525]

Thanks for the info! I'll ask my dealer how much it is to program the key and go from there. Does anyone know how to tell the difference between CA vs. NON CA key fobs?

[Dpc2u]

Replaceable battery, CA. No replaceable battery, non-CA.