Car unlock with xEM SUCCESS

Hey guys, I hope everyone’s weekend was as good as mine.

On Saturday I wired an xEM access controller into my car’s locks, a 2013 Hyundai Veloster. I ran the antenna into my side mirror since the doors are metal, and it seemed like the most ergonomic approach. I wish I had taken some pictures to give you guys a proper write up, but when I get the itch to do a project I don’t think of such things.

It was a fairly simple but time consuming project. I removed the mirror and door from the car entirely. I used silicone wire to extend the antenna wires, just to have some extra wiggle when folding the mirrors. I had to run a [fused] power wire through the factory loom/weatherproofing into the door to power the xEM. I was originally going to tap into power in the door, but it turns out that all power to my door is lost with the courtesy timer for the interior lights and such. The lock switches themselves ground a relay in the fusebox which actuates the locks. This was a benefit as it’s very low current draw, and I was able to simply jumper the unlock wiring straight through the COM and NO on the xEM. No need to add an automotive relay to the circuit.

All in all this was about a 6 hour project, mostly because I’m very compulsive with wiring. It turned out perfectly clean and works great.

I posted this to an automotive group and let me tell you, they did not take it well. Mark of the beast, stupid, waste of time, “it’s gonna be so easy to break into your car now” etc. One guy even called me a dweeb :grin:

I want to thank all of you for existing. These sort of things bring me a lot of joy, and none of it would be possible without all of you keeping this niche interest alive.


That’s pretty cool. I really like the positioning.


Putting it in the mirror is a clever idea.


Nice work.

Just the RFID to unlock? and manually lock?

Can you share the link?
I’m sure im not the only one wanting to read your post…and comments

Compared to the tried and true method of breaking a window? Or shimming the door open a little and using a long reach tool to press the open button on the other side?

Yeah, knowing you have a chip and that there is an access controller embedded in the mirror, and then capturing your chip details and replaying them. That really is so much easier.


Yeah it just unlocks it. I considered my options for making the car also unlock with my chip, but decided that I’m fine with just hitting the lock button when I get out of the car

It’s a private group on Facebook so there is no share button, but I can upload some screenshots

1 Like

Scrolling for the skynet comment. Found the skynet comment. :joy:


I’d say there were at least a good number of positive comments. Perhaps not the majority but still.

How do you deal with current draw? I have a lot of issues with an empty car battery with my accessories hooked up (dashcams).
Even the power supply which is designed to cut-off at 11V pulled enough current to drain my battery after sitting at the airport for only 18 days.
Maybe it‘s just another problem with my car but if I install such technology, I need it to be reliable. Not getting home because of a drained battery is no option for me anymore. :grinning_face_with_smiling_eyes:


It draws ~100mA which isn’t really a problem for me. The longest my car will typically sit is over the weekend. I think 18 days might cause some issues though. I have a toggle switch on the power wire for the access controller in my interior kick panel fuse box. Just in case I ever feel the need to disable it for a period.

I toyed with the idea of adding a small independent 12v battery to the xEM access controller, with a 12v-12v charger wired to the ignition circuit. That way when the car is running, it’s charging the battery. When the car is off, the access controller runs off of its own battery. Then if the xEM battery dies it wouldn’t drain my car battery, I would just have to use my key or my fob to unlock the car like a Neanderthal :joy: I ultimately decided that I was comfortable with the xEM’s current draw. Plus my car is a tiny stick shift hatchback and I’m spry enough to push start it, if it comes to that