F150 RFID push to start/door unlock

Thanks guys. I’m a little new at this. I don’t have an implant yet but I have 2 RFID bracelets. One is a em4100 and the other is a t5577. From what I understand the 4100 won’t write is that correct? I also have one of those blue RFID reader/writers would that be enough to write the access module fob to my bracelet that already has the easy guard fob wrote to?

I would suggest you enroll the bracelet to to the “access module” as you call it.

There are a couple of ways to skin this cat, but,
This is what I would do
Take your bracelet (EM4100) and enroll it into you Push to start,(learning mode) then using the same bracelet to enroll into your “access module” (present master and within 3secs present bracelet)
TaDa :mage:
One bracelet to rule them all :ring:
Then I would buy a NExT, FlexEm or xEM so I didn’t have to wear a bracelet!

(I can do a more thorough write up to explain the what’s and why, if you need it, I am just on my phone at the moment so keeping it brief)

if you want to enroll your t5577 bracelet, this is where you would use your blue cloner

FYI re: the blue cloner
Check out this video if you haven’t seen it.

Excellent thank you! I think I got it just need to wait to get my handles on the xEM access controller when it comes back in stock, or did I read correctly there might be a new version coming?

You did and there already is…
I don’t know if DT have the original xAC still in stock, you might have to ask Amal

Here is the link to the xAC V2

and the video (there will be more coming), as Amal says in the video, next is Garage door wiring with the xAC V2

Awesome! Ordered. I’m guessing it would be pretty simple just to build a custom harness to add additional antennas? Maybe this for example? I was thinking of 2 on the front of the vehicle and 2 on the rear. Probably overkill but I’d be able to unlock the doors any side of the truck which is a nice thought

There are ways to have multiple “antennas” where you switch between them one after another afaik (think it is called antenna multiplexing).

Not an expert on this but I think running all that cable might cause issues. See this post:

You also would need an identical antenna (or at least identical impedance inductance I think, unless the new xAC has the tuning cap under the blue tape.

You could also just have 4 xAC modules :sweat_smile:

Haha I could do four! Worse comes to worse if I can do a front drivers windshield with one additional rear drivers glass antenna that would be good enough. I suppose the specs on the antenna hasn’t been posted yet as it’s new? At least I could see or find any

Matching the inductance is the most important thing, and I’ve provided that measurement here;


The tuning cap would very likely be on the board. I think the blue tape is simply concealing a horrific soldering job.


My hunch is that this would not be necessary. I am pretty sure you could simply extend the existing antenna using speaker wire… that small gauge wire that is in housing that is stuck together side by side. It’s important that this be the case so the wire doesn’t wrap around it self… try to keep it flat with no twists and don’t wrap it around stuff if possible… that will keep the effects of running such a long length to a minimum. If you have twists or wrap it around things that will create additional inductance that will throw off the tuning. I can do some tests with this type of wire soon and let you know.


Thanks! In my head typing that 8t felt off… Was in a rush. Fixed :sweat_smile:

Thanks man. That would be great. In theory if I did go the 2 antenna route would I be able to replace the included antenna for those antennas posted and just splice in the extra one and run additional wires?

And thank you to everyone else for the assistance. I misread the wiring diagram on my compustar alarm and the wiring I was hoping to use is actually a trigger to remote start the truck, not unlock the doors. I might just end up soldering wire to an extra fob I have to simulate a button push. I’m not so worried about locking as the F-150 has a door mounted key pad that I can just press a button to lock and arm the system (love that feature) this might be the way I end up going unless I can find a setting in the compustar DC3 to do what I’d like it to do!

So you are going to have:-
easy guard RFID push to start
compustar alarm
xEM Access Controller v2

Have you done the power calcs?
easy guard RFID push to start 8mA idle ( Claimed, I haven’t tested )
compustar alarm, will depend on which model you have
xEM Access Controller v2 60mA idle (xEM Access Controller is 11mA)

Yes sir thank you, I have a high capacity AGM battery for all the electronics. Should be good with the Idle draw.

Not likely. Here’s why;

Would I be able to make another one out of similar wire though or just extend the length?

Yes, you would need a LCR meter (so you can measure inductance). If you get the inductance the same it should work, but that’s why off the shelf won’t work unless you get particularly lucky.

This post has some good information, there able to get away with not having a LCR meter as the device there adding it too can measure the antenna characteristics itself.

So to simplify this and not having to worry about the antenna, I think I’m just going to get a second xAC v2. Here’s my plan, and please let me know if anyone sees any issues with it or a better way.

Solder 2 wires (+ and -) to the key fob, from this wire set, solder an additional + and - for the second xAC v2. One xAC will be at the front drivers window, the second xAC will be at the rear drivers window (or possibly passenger side)

Also since the xAC is providing the 9v pulse, I wouldn’t need to have the battery in the fob correct?

Amal - could you please provide the measurement of the board? I didn’t see them listed

What are you connecting it to on the fob? I doubt your fob conveniently has a place you can pump power into that will both power it and press the button. You shouldn’t need a battery, you could power it from the car but the fob probably expects a 1.5v button cell, you’d want a voltage regulator hooked up to 12v from your car. As for activating the button, you can’t just dump power into the button pins, that’s a great way to release the magic smoke from your fob, you’d want a relay or MOSFET of some sort to replace the button.

(sorry not an electrical engineer so may be wrong with terminology etc)

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@leumas95 looks like he is replying to you ( A couple of issues with your plan, or things to confirm ), I will leave him to it, but I will give you the measurements…standby
Call it 105mm x 55mm to be safe
xEM is implant
xAC is the access controller V2

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Right sorry, 2 am and my mind isn’t working clearly lol I’ll edit the post to avoid confusion. Thanks for the measurement. Is that the v2? That is the one I ordered as the original is out of stock.

Yes, directly to the fob. I can’t really see another way to do it. My original plan was to tap into my compustar unit to unlock/disarm the alarm but I don’t think there’s a disarm input from what I saw. That’s going to be the issue. I can run it to the lock wires to unlock but that won’t disarm the alarm. Seems like this is going to be more complicated than I thought

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