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DIY Tesla Key

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Nick77

Deep Blue Model 3 LR (2021 MIC)
Mar 15, 2020
761
397
Burton-on-Trent
A what I did to my Tesla today type thread.

I wanted a backup for my phone key just in case my phone died in any way while I was out. I don't like carrying the key card around with me as I don't take a wallet out with me any more, and I'd only end up losing it or leaving it in the wrong trousers/jeans when I needed it.

Saw how much Tesla rings were and thought eff that! Plus I don't like wearing rings, and was only going to put it on my key ring any way. So I thought I'd make my own key ring key.

I saw a video on YouTube of how you can get the wiring/antenna out of any Tesla key card by putting it in acetone which dissolves the plastic leaving it like wet tissue, but the antenna is still intact.

I have a warped key card sitting there bugging me, so decided to butcher that. Bought an inexpensive (£3.50 delivered) blue key fob off the internet with 25mm plastic window inserts front and back. And a bottle of acetone from Amazon (£2.99 delivered).

Popped the Tesla key card in the acetone for an hour or so to dissolve the plastic, dried off and wrapped the antenna around my thumb to get the correct ring shape (if you fold it over on itself it doesn't work for some reason) and then pressed it into the key fob insert.

Printed out a couple of snazzy blue Tesla logos for the inserts and popped it in over the antenna so you can't see it. Voila, my own stealth Tesla key fob. Works perfectly for opening/locking the car and driving. It was already programmed to my car so didn't need to do that either.

Unlike a key card, if anyone finds my keys they wouldn't think it was a key to the car, just a cheap keyring.

Total cost £6.49.
 

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I'm not sure how well your "poor taste camouflage" will really work there, if you don't know that Tesla are minimalist that looks like something interesting. Put a Renault logo on it instead and no one would bat an eyelid.
 
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I'll probably get rid of the "keep calm" keyring tbh. I bought that for the same purpose but can't get it apart for love nor money. Plus it's too big in my pocket.

Plus if they didn't know Tesla was minimalist, they wouldn't know to press it against the door pillar like a key card.

No issue any way as I don't ever lose my keys.
 
Just been having a look for key fobs and have yet to see one like the one you used. Do you mind sharing the source?
Yeah no problem.


There's all sorts of different types, colours and sizes on that site. You just need something you can either open up and close again or a little recessed window like mine.

May as well put the acetone here too:


If you do it, just make sure it all works ok with the car before you push the plastic window in, as it's a tight fit and a bitch to get back out.
 
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Yeah no problem.


There's all sorts of different types, colours and sizes on that site. You just need something you can either open up and close again or a little recessed window like mine.

May as well put the acetone here too:


If you do it, just make sure it all works ok with the car before you push the plastic window in, as it's a tight fit and a bitch to get back out.

Thanks for that. I've just been looking at a SMART car replacement key fob case: Smart Car 3 Button Remote Key Fob Case For City Roadster Fortwo Forfour Coupe | eBay
Do you think there would be any issue using something like that?
 
As long as you can secure the chip and the wire all inside without breaking it, and without folding it over on itself, then it should be fine.

Good news is the key cards aren't expensive if you do damage one, so you can just try again.

I ended up using the Smart car fob case (£2.99 on Ebay) which has plenty of room inside but is still not too huge. I had previously seen this video
of "dissolving" the card to reveal the internal RFID electronics. There may be better sources for the antenna folding techniques than in that video though. Attached are pictures of the card with the plastic coming apart, the internals and the fob itself back and front. By the time I had got the wiring in a working position, and clicked it together, I wasn't going to take it apart again for a photo shoot of the messy folding inside!

I'm not sure if the plastic actually dissolves as such. Rather it turns into soft flakes with some needing to be delicately picked off. It took about an hour and a half of submersion in the acetone (used about 125ml) ... in a ceramic bowl borrowed from the cat.

My card had almost split by sitting on it whilst in a back pocket and the antenna wires had a little nick that looked like a weak point so I was wary about extreme folding so that was one reason why I used a bigger fob. I should comment that using the fob without scratching the car would require holding any attached keys safely out of the way ... particularly when placing against the shiny plastic centre console to "start" the car.

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are you able to avoid the centre console nonsense if you get in and hit the brake quickly? or is it based on when you actually drive away?

and anyone on Etsy or similar selilng these premade for sausage fingered types?
I can’t think that you can bypass the console reader. Rings made from the rfid cards are available from several sources last time I looked (which was probably a year ago).
 
I ended up using the Smart car fob case (£2.99 on Ebay) which has plenty of room inside but is still not too huge. I had previously seen this video
of "dissolving" the card to reveal the internal RFID electronics. There may be better sources for the antenna folding techniques than in that video though. Attached are pictures of the card with the plastic coming apart, the internals and the fob itself back and front. By the time I had got the wiring in a working position, and clicked it together, I wasn't going to take it apart again for a photo shoot of the messy folding inside!

I'm not sure if the plastic actually dissolves as such. Rather it turns into soft flakes with some needing to be delicately picked off. It took about an hour and a half of submersion in the acetone (used about 125ml) ... in a ceramic bowl borrowed from the cat.

My card had almost split by sitting on it whilst in a back pocket and the antenna wires had a little nick that looked like a weak point so I was wary about extreme folding so that was one reason why I used a bigger fob. I should comment that using the fob without scratching the car would require holding any attached keys safely out of the way ... particularly when placing against the shiny plastic centre console to "start" the car.

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Nice work! Did it all wrap round inside the fob ok or did you keep folding it until you found a configuration that worked?

The weird folding behaviour in that video is the reason I went for a wrap round and round my thumb configuration like the DIY rings in this video:

 
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are you able to avoid the centre console nonsense if you get in and hit the brake quickly? or is it based on when you actually drive away?

and anyone on Etsy or similar selilng these premade for sausage fingered types?
I just tried and I could just unlock, get in, and drive. No need to touch it to the centre console.

Edit - Although I now realise that my phone may still have been in range and connected when I just tried it.
 
Nice work! Did it all wrap round inside the fob ok or did you keep folding it until you found a configuration that worked?
I would have been neater doing it your way but I got a working configuration pretty quickly anyway. I hadn’t seen how it’s done for the rings but I did realise that the folding in the video wasn’t giving a very useful steer. Anyway, thanks for triggering my interest in doing it!
 
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Just curious. Has anyone accidently or otherwise, tried to wireless charge their phone with a Tesla keycard sandwiched between charge pad and the phone? Even more interested if it was a magsafe iPhone.

I'm thinking about seeing if a keycard or its mechanism might be able to be placed inside an existing phone case. Just not sure what the interaction of the charging field on the key card et. al. would have.