Car access and start

Right new project, I want to walk up to my car swipe xEM it will unlock then I can swipe on the dash to start the car. When I had my motorcycle I used an xEM controller to eliminate the key on that so why not with a car?

I’m going to get a xEM access controller probably for the unlock and use one of the elcheapo pushbutton start kits for the start. Going to need an imobiliser bypass module and a spare key to cut and disable the steering lock.

Anyone done anything similar?
Feel free to pitch ideas I’ve want to mod my car to the limit with rfid tech haha

Did you check out the similar ones here in the project section, if not, you might get a couple of ideas
This one
This one

You can definitely do it that way, for mine, I decided against it and just removed the lock barel, worked perfectly, and the Push to Start Button slotted in perfectly into the sterring collum shroud.
If you require a key chip, this can be removed from a key and placed next to the antenna coil.

Have a read through those links, I’m happy to answer any questions I can.
I hope to carry on with mine in March, so keep an eye on my project, that I will update as and when; Unless you get yours done first and I may just copy yours. :smirk:

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Yep, done similar!

Mine was a touch more complex since my car has an alarm i needed to disarm on swipe before unlocking, and I use alarm state to enable the push-button so I don’t need to swipe again once in the car (I already have swiped to authenticate myself before sitting in the seat so I felt it was unneeded).

Sounds like you know what you want to achieve and how to get there, so not much to add to the mix. I’m using an xEM access controller for the drivers door - only food for thought is that I’m adding another 2 access controllers, one in the passenger side and one in the tailgate for when I want to put things in my car before I sit in the seat and drive away.

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Counter-opinion: I went with a cut key to disable lock - it has no chip and can’t bypass the alarm and immobiliser so nobody can start the car with it. Went this way so if i leave the car unattended for a period of time (airport parking, etc) I can just remove it to put the lock back on - also does keep the key lock functional incase my $30 eBay push button start decides to not like me at any point.

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Fair points, and I guess you can argue either way. For me it did it because I could, and I thought it was a cleaner look for a similar result

I had mine installed for about 2 months and it didn’t skip a beat, I took it out to work on my upgraded version.

I also have my car unattended for long periods of time when I travel, so Battery drain was a consideration, I thought about a VSR to a small house aux battery with a low voltage cut out to run the mods and a ‘hide a key’ as a backup, but my current thinking is just a Momentary button so zero battery drain ( but will still have a ‘hide a key’ as a backup, just in case!!! )

Pilgrimsmaster linked to my post earlier and i will be updating it soon (spring break maybe). I just need to get my parents to let me do it lol (im only 17 so i still live with them). but for now, I plan on using the easyguard ec004, installing as intended, and also dissecting the control box to run a wire from whatever goes hot when authenticated to a relay to unlock the door. Check my original post for more detail or wait till i finish for an update

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Yep did see them, if i am honest this thread is more for me to keep a log of my doings and if that helps people great!

i wounder if we can source the antenna for the xEM controller separate (im thinking replace the easyguard antenna with the xEM one as it would be significantly better at reading a implant.

I modified a reader years ago with the xEM antenna (i cut it off) and it worked 100% better so why not here.

Also i am unsure weather i want to use a controller or build something arduino based, either way i will document this to the best of my ability to allow others to learn from my mistakes

I also wondered about the Antenna swap, I was dissuaded for doing it, due to some comments made about tuning etc. I may also still do it or at least try it, depending on the factory ring antenna performance. Through Windscreen was my original thought, but I am swaying more towards putting it behind the wing mirror, so just through plastic which SHOULD give it a better chance of reading, plus I will probably put the momentary button on the underside. If I manage to get my testing done before you, I will update you as to the performance differences…if any

This was from turbo2ltr when I suggested the antenna swap

FYI, I looked for seperately sold xAC antennas but came up dry, feel free to have a look, you might have better luck, I was going to just grab another xAC to take the antenna from it

i did read that however due to the low frequency of 125khz and the fact most readers use an antenna that is a simple inductor more often than not you can get away with it.

i did find several encapsulated antennas that may work, if im honest im thinking i may just mount the antenna external to the car say on the bottom of the drivers side wing mirror.

Sounds promising, I eagerly await your results :smiley:

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Right kind of a cross post as been lending a hand in another topic but thought I would post it here to.

I’m making a circuit that will fit inside the xAC and will open and close the care using a modified keymote.The circuit, it works in principle I’ve driven LED’s on the outputs and the blink very quickly (may be too quickly).

Hopefully the circuit makes sense any questions I will do my best to answer.

I’ve gone and done a board, I’ve kept it as small as I can without making the soldering too difficult. Board measures 25 x 28 mm, I’m going to order a handful once they arrive I’ll put them together an we will see what happens.

P.s. at this size more than capable of fitting inside the xAC.

P.s.s. believe the board can pick up 5v from the xAC controller board but am unsure on current consumption (how much over head is available in the controller) worst case a 7805 tacked inside will do the trick.

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Unlock would be pretty simple. Just run the 12v to the battery and the ground somewhere nearby on the chassis. Then run the signal wire to the unlock button. I would also recommend adding a little physical switch that you can hide somewhere on the exterior of the car, maybe in the grille, so you can turn off the voltage to the access controller by switching that little switch for added security and not to drain the battery. Starting the car is a whole different issue. In my case, my BMW uses a CAS module to verify the key, VIN, and some other things so simply replacing it would render my car a very expensive brick. But since it is already push to start, I can move and hide the original factory key slot and leave the key in there at all times. I have to plug either a buletooth dongle or a K+DCan cable into the OBD2 port and code my car not to eject the key when ignition is turned off. Therefore I can leave the normal key in and hide that somewhere under the dash but be able to take the key with me when the car is going to sit for a while. Find the signal wire from the key module to the stock push to start button and wire either another access control module or NFC between there and put the antenna where the stock key hole was which is just a couple inches under the button. Then I can hold my hand up to the reader and click the push to start at the same time while having all the verifications sent to the CAS module. That’d kind of overdoing it as there 4 forms of verification… RFID, NFC, Physical Switch, and the original key itself. Think of it as being impossible to steal, even better solution than a manual transmission nowadays! Having an amplifier for an aftermarket subwoofer almost makes the unlock aspect plug and play. You can also use the remote wire from the amp or radio to pull 12v for your start antenna. When you unlock the car voltage is sent through all the electronics for a little bit but turns off after a while without any activity. So you’ll have anywhere between 30 seconds to 4 mins, depending on your car, to start the car if using a remote wire like the cigarette lighter or radio until everything turns off again to not kill the battery so you’ll need to click unlock button again to wake it up

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That’s a lot to deal with but let’s try :slight_smile: first of this is all really good info and is appreciated.

The idea is to only require absolutely minimal modification to the car. The xAC has a idle current draw of 11mA at that rate the battery would last multiple months before any issues. I do like the idea of an external button but didnt like the idea of hold a button scan a tag and open the door all at the same time. That being said a hidden switch that could turn off the xAC when the car will be unused for long periods of time.

The signal wire of the xAC outputs 12v when an authorized tag is present attaching this in any way to a keymote would cause damage unfortunately.

Also not my car specifically uses a switched ground for almost all triggering which also complicated matters.

I also dont have a 12v remote wire and my cigarette socket is live always typically.

I’m going to focus on one part at a time so were going to get in first, once that’s dont I think I’m going to get and modify a push button kit but we will wait and see.

I’m a mechanic and I’ve been doing this for years! It’s not all that complicated and you definitely wouldn’t be hitting a button, scanning, opening a door at the same time. Just scan and it’s unlocked. The button is there in case you want to turn off that reader for some time if you don’t like the area you’re in. Once voltage has been sent to the unlock sequence… it’s unlocked. No need to wire it like an RFID door that needs a capacitor or it only opens when it’s activated because that actually could cause some issues.

I find this a slightly difficult to believe although some cigarette lighter are always live, and some head units dont have a remote line, I’ve just never seen a car that hasn’t had some remote wire somewhere. Ether way you could just order a LOC, Line Output Converter, that will tap into existing speaker wires and give you a remote wire, 12v, if you don’t feel like ripping your dash apart to use a voltmeter to find the right wire off the right fuse.

Installing a new ignition switch is entirely specific on your car but still pretty universal wiring so it shouldn’t be too bad. Most of the work will be trying to find the right wiring diagram.

This entire project shouldn’t take longer than an hour nor require too much thought so don’t stress yourself too bad over this. It’s just a few wires. Even just taking it to Car Toys, the 16 year old working in the back could have you taken care of in just a few hours XD.

Best of luck to everyone taking on a project like this! They all differ in some type if way and no one way is best. Do what works best for you :+1:

Car mods are easier than they look! After spending probably 4 times more on aftermarket parts than what I bought this car for, I can safely say that this is one of the easiest mods to do with minimal modification. It can easily go back to stock in the matter of minutes if you need to sell the car.


I have re read both of your comments and realised I misunderstood several thing.

Were both on the same page as a switch to disable the xAC.

Just to clarify I have a 2011 zafira, I want to scan my chip enter the vehicle and then start the car (dont want to scan again).

I was imagining figuring out a way to modify the xAC and a push button start kit so that the xAC handles the authentication and just goes high to allow the imobiliser bypass module to work and the push button to be enabled.

Yeah I saw were were on the same page just slightly misunderstood eachother with slightly different ideas. You should be able to piece it together the kits fairly easily. Essentially just hotwiring the car to a push button. That will bump the starter after getting it’s voltage from the signal wire.

You own a car I’ve never even seen in the States so I hope I can be of some help.

Wire up the xAC to constant 12v, and ground. Use a hidden switch if you liked that idea. Then run that signal wire to your unlock button. Your car gives of 12v somewhere after being unlocked, you just have to find it, and wire up your bypass module to that. Then install your push button and you should be off for the races with just one scan.

This would be more secure than a typical turn style key if you can keep the RFID safe. Trying to hotwire this would take a lot longer than just shoving a screwdriver in the key hole XD. Be sure to hide the antenna in the A Pillar of the car.

I love your project and design! Don’t get me wrong. Over engineering is my kind of thing! I just believe it’s slightly over complicating something meant to be fairly simple.