Parts For Sale 2x Key FOBs for sale (left from my totaled 2018 BMW i3)

BMW i3 Forum

Help Support BMW i3 Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Parts For Sale
The only real value for these key fobs would be if another i3 or i8 owner needed to swap some damaged parts; the fobs themselves can't be made to work with any other i3 or i8.

I have read a few claims that with some really specialized equipment, fobs could be made to work with a different car. However, I've not read about any i3 or i8 owner who has successfully used fobs from a different car.
 
In fairness, some people do give their key fobs a really hard time, and I'm pretty sure that the plastics used on an original key are better than those used in the cheap Chinese-made "key fob case and blade" replacements you can buy on Ebay. You could probably use parts from these to refresh worn bits on heavily used keys?
 
Damn shame BMW is so draconian about their keys. I need a backup key (bought used, only came with one), but this will not work for me. Also, Bimmertech is no longer able to do keys for people, which means dealer only. Ridiculous.
 
Yes, the cost of getting a second is an unwelcome surprise to those of us new to BMWs.
There are some on-line BMW dealers that sell fobs for somewhat less than what they would cost at a dealership. Proof of ownership must be demonstrated and the final step of pairing a new fob with one's i3 must be performed which isn't difficult, apparently.y
 
I just ordered a 2nd fob and the used car dealer I bought the car from got it for me from the BMW dealership at their cost, which is 20% off (and it was really nice of them to do that for me) but still over $400. He said they had to order it from the factory (after verifying my lic and reg) and have it coded and shipped (so the key would fit my doors I suppose) and therefore if I'd bought one privately, it wouldn't have fit my car. This is just a disgusting way for BMW to ding us all for triple the actual value of one of these things just because it's a BMW. Ooh, fancy car, gotta pay more for a key.
 
When I bought my 2009 535xi wagon it only came with one key. BMW wanted $710 CAD for a second fob (comfort access) which was out of the question. Fortunately a guy locally on Craigslist had a key programmer and I paid him $150 for a fob and he programmed it, then $50 to a local locksmith to have them cut the key blade.
 
When I bought my 2009 535xi wagon it only came with one key. BMW wanted $710 CAD for a second fob (comfort access) which was out of the question. Fortunately a guy locally on Craigslist had a key programmer and I paid him $150 for a fob and he programmed it, then $50 to a local locksmith to have them cut the key blade.
I wonder whether that's still possible. Car manufacturers have been increasing the security of their keyless entry systems, so maybe BMW is now the only source of fobs.
 
I've seen some CCTV videos of scumbags wandering around the front of properties using what's called a 'relay technique' getting the signal from the key fob in the house.

Is the i3 susceptible to this kind of snooping or is it only those that have Comfort Access? Think I'll be putting it in a piece of tin foil in the future!
 
I've seen some CCTV videos of scumbags wandering around the front of properties using what's called a 'relay technique' getting the signal from the key fob in the house.

Is the i3 susceptible to this kind of snooping or is it only those that have Comfort Access? Think I'll be putting it in a piece of tin foil in the future!
We have a metal box in a cupboard by the front door and all keys are dropped into it once we enter the house.

Although my understanding is that car thieves focus on two groups of vehicles; expensive ones - e.g. Range Rovers, Mercedes G and S class for which they already have orders, and popular ones like Toyota, Honda, Kia which are stripped and the used parts sold into a thriving black market. I don't think that the i3 fits into either of those groups, and - it's worth remembering that thieves are in it for the money they get - if nobody wants to buy the stuff they steal, then it's not worth stealing it.
 
Is the i3 susceptible to this kind of snooping or is it only those that have Comfort Access?
As I understand it (and as discussed on other i3-specific forums) it is not. If you don't have Comfort Access, the key only transmits when you press a button. Otherwise it's silent, and there is nothing to "relay" to the car.

And, as said - it doesn't seem at all popular car with thieves. That may vary by location, but in the UK it doesn't appear anywhere on the "most stolen" statistics.
 
I think I remember reading that the BMW fob comfort access transmission is motion-activated
But apparently motion-sensing was only added later in production. Some time in 2019? Not a feature that's present on my car, and I don't regret that. I've never found it too taxing to press a button on the remote!
 
There's a bit of confusion on here about how Comfort Access works. The door handles (and rear bumper for the rear hatch) have a small antenna in them that broadcasts when the door handle is pulled or the touch-sensitive area of the handle is touched. This signal only goes about 1 meter. If a key fob is within that 1 meter range and picks up on this signal from the door handle it sends a reply to the normal antenna used for key fob operations, similarly to if you had pressed a button on the fob, if the car gets this reply it unlocks accordingly. Then there is another antenna inside the center console whose purpose is to detect if a key is inside the car. This antenna broadcasts when you press the car start button and runs through the same procedure. There is another antenna inside the rear hatch area to detect the presence of a key inside the trunk when it closes so that it can open it again so that you don't lock the key in the trunk.

I have also seen videos of people walking down the street with large antennas and stealing cars. Whether those are legit or not, I don't know. Perhaps they are picking up on the signal from the car door handle and amplifying it greatly to the point that the key thinks it is next to the door handle and tricks it into sending out its signal. I tend to doubt it's that easy, but that's all I can think of.

One of the attached document is a few older than the i3 but I doubt that the design would have changed that significantly.

On the E60/E90 you can disable comfort access by inserting the key into the steering column slot. This was necessary when washing the car because each time the door handle gets sprayed by the hose and you're close by with the fob in your pocket it keeps locking/unlocking. I don't know if there is a similar ability for the i3 since there is no slot for the fob. Perhaps if you leave it in the interior or something like that.
 

Attachments

  • Comfort Access.pdf
    1.6 MB
  • Comfort Access TIS i3.pdf
    395.7 KB
  • Comfort Access aerials.pdf
    156.5 KB
Last edited:
I tend to doubt it's that easy, but that's all I can think of.
On some cars, it really is that easy, apparently. A simple relay process to makes the car and key detect that they are close together when they are not.

On some cars - such as some of the recent Kia and Hyundai models, there are other weaknesses. Apparently these relate to the strength of cryptographic keys, and some very bad design decisions/shortcuts being made - but AFAIK that doesn't apply to any BMW models.

I've never heard of people walking along the street with antennas, stealing cars. In the UK the technique is almost exclusively used in targeted thefts off driveways, because then it's easy to associate a car with a property, and to target the part of the property where people normally leave their car key (i.e. right next to the front door).
 
Back
Top