Car Key Mod With Electronics




Introduction: Car Key Mod With Electronics

Hi DIYers :)

Inspired by a bit simpler project with HotWheels car model and no electronics by user schnurrbart, project is here: Hot Wheels Car Key

so, lets get started... or wait... before you commit to such build, please make sure your solution will work and ALL electronics will be compatible. I'll explain later ;)

let's go!

Step 1: Choose Your Model and Bear in Mind That Electronics Need to Fit As Well!

Here's what I did:

1. found a lovely companion whom I took to children's store to hang out and search for different models and variation of producers

2. chose around 6-7 models and started measuring in shop for rough fitting

3. checked how the models are assembled (screws vs. stamped metal)

4. experienced the childhood happiness from hanging in a TOYSTORE - very emotionally positive start to such a funky project :)

5. get home and like Mark Watney said in Martian: "Science the s*it out of it"

Step 2: Make All Parts Really Fit

the geek part is now!

You have to make all the parts fit and stay in place without too much pressure!

I had to cut the mid plastic part out, the saloon part of the car. And thank you TOYOTA, they made the in-key electronics part with VERY good shape for custom builds :)

Bottom plastic part was just cut without measuring or much attention, small holes to fit approximately button positions and then made them bigger step-by-step until they fit the buttons nicely.

next step is chemical metal :D

Step 3: Prepare Your Gloves or Just Use a Lot of Cardboard

to fit the physical key in position very strongly I used chemical metal - dunno if this is technically the right term but this is how we call it here :D

It is 2 component fixing paste, you just have to follow the instructions that comes with the package - every producer has different requirements.

I just squeezed approximate amounts and it worked very well. Instead of gloves I used 2 pieces of cardboard, one bigger on wich to mix and second one to apply the ready mixture.

NB! most of the chemical metals dry/cementisize :D (become strong) VERY fast.

NBB! don't be greedy, make at least 1 test, I did 3, meaning that I used same amount of mixture just for nothing, just to see how it blends and how fast it fixates. Learned a lot! Especially the fact that if you mix it for too long, well... you can't mix it too long, it will just become one solid piece :D

My suggestion, take 3/4 of the mixture you prepared, apply it fast in "general places", take the last 1/4 and try to squeeze behind the corners and "make it pretty"

As this step is all about the physical key, lets wrap up the front of the model:

grill was originally part of the mid plastic panel, but had to be removed as chem.metal took up the sacred space ;)

I cut off the grill and even managed to mess it up with lower&upper side, but in the end that didn't affect the general look ;) - but YES, my soul screams out for that mistake :D :D :D


here is the HA-HA of my project

as the models body is made of metal and the position of the electrical part of the key is not the same as for original key the immobilizer of the original key didn't work.

I was ready to call Tony Stark for help, but figured out after some testing that the car starts with original "untouched" key and doesn't with my new DIY edition...

another disassembly found place to be, I had to disintegrate the backup key to get just that little piece that is now glued to the lower part, and yeah, don't worry, the wheels are still spinning and the model is driving ;)

NB! for positioning of the immobilizer "sensor" please spend some time as it turns out that they don't work in all positions or angels!

Step 5: Figure Out How to Close and FINITO

If you chose a model with screws or bolts then you're good to go!

But if your model had stamped metal ends, then you need to find a way to close your project nicely.

I turned again to the chem.metal described couple of steps earlier.


- holds up very good

- simple

- can still scratch it off if needed - i.e. battery change - I did replace it ;)


Homemade Gifts Contest 2015

Participated in the
Homemade Gifts Contest 2015

Be the First to Share


    • Game Design: Student Design Challenge

      Game Design: Student Design Challenge
    • Make It Bridge

      Make It Bridge
    • Big and Small Contest

      Big and Small Contest



    7 years ago

    the number 1 reason for the failure of car ignition is that heavy key chains will apply large unecessary torque onto the ignition housing. I recommend being careful with the weight of the car you put on the end of the key and maybe even turn the car sideways to reduce torque. so if you're having trouble with the car starting when you turn the key, a heavy Keychain is most likely the cause even if you no longer have a heavy key chain

    DIY Hacks and How Tos

    Fun idea. I know a lot of people who would love custom keys like this.


    Reply 7 years ago

    thanks ;)