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  • keypad

    Alright i searched and read alot of threads on this idea. but there were so many pages i didnt read them all >.<. basically... i wanted to see what u guys thought about this.

    a keypad from an access control system or one of these with a mobile os such as android or even winblows CE. with a simple app designed for a certain passcode which when entered correctly, would disengage a killswitch(somehow im not sure how i would do this seeing if i used a relay i would need a constant charge from the device , i think) which would in turn let me start my car. do you think its reliable?

    like i said before.. yes i did

  • #2
    There is no easy way do do this. You would amongst other things need a sepperate power source for the keypad device, that charges while the engine runs.

    On cars where this is an option from fabric, they do not cut any power but the block the ECUs of the car to go active. Like an anti-theft system.

    Now then... splicing into the ECUs is a risky business and if you're NOT an electrical enginere from your very own car moddel. I would strongly suggest that you drop this issue.

    I had a extreemely modified car once that I did some programing on. We had the whole performance bit of the car be diagnosed and configured from a PDA. (This was back in 2000 and CarPCs where not that big then).
    The car ended up with three power modes...
    "Wallet" - power cut at 3000 RPM and max speed limit at 30 km/t
    "Wife" - Power cut at 4800 RPM and max speed limit at 150 km/t
    "POWER" - No Power cut, no speed limit. Just pure 634 HP at the rear wheels.

    This where in an extreemely modified Volvo 960.

    The whole job was a hell to acomplish and I ended up with frying 3 ECUs before we got the car as we wanted it to be.


    • #3
      i dont know what your talking about >.<. LOL!

      i just want to do a simple killswitch, but instead of a switch, have a keypad. and yea i realized about having to power that device. but i could have it powered by a proximity RFID, or i could just use a simple keypad they use for access control. im pretty sure you dont have to do anything with the ECU if i just wanted to make a simple killswitch but then again what do i know? thats why im posting here >.<


      • #4
        ok so i found this on basically this looks like a setup i could use for this keypad and it seems like it would work pretty well. i dont know how to understand wiring diagrams really (i know retard huh) lol and i dont know really how this works but it looks like it could be used for my setup i want to make. basically it uses the momentary switch to "latch on" im guessing to keep the relay closed after the IGN has been turned on by the key. from the discription on

        This is a stand alone starter kill. It does not rely on an alarm or keyless entry for it to work, only a simple momentary contact switch (normally open) to deactivate it. Every time the ignition is turned off, continuity is broken on the starter feed wire. To disable (or start), turn ignition on, then press the hidden switch, then start as normal. You can substitute the switch with a number of others devices such as the amp turn on wire of your head unit. Be sure to isolate it with at least a 1 amp diode. Turn the key to the run position. Allow the head unit to come on or turn it on. Now start the vehicle. If you connected to the power antenna wire, make sure the tuner is on. If you have a pullout or detachable face head unit, your vehicle will not start without it.


        • #5
          Originally posted by krillik View Post
          a keypad from an access control system or one of these
          Dead link.


          • #6
            This is what he was trying to link, I think.

            If it was me doing it, I'd probably end up using an Arduino mated to a numeric keypad of some sorts. The Arduino would enable a regular relay that would go inline with my ignition switch. I was strongly contemplating doing just such a thing, but in the long run, a simple kill switch would be safer and simpler. K.I.S.S. is often under-appreciated. If the Arduino should happen to fail, you've got to do some disassembling and rewiring before you can start your car.

            It's definitely got cool-factor to punch in a code to start your car, but then, why don't any manufacturers do that? There must be a reason. Sure, some new cars use some sort of RFID or something, like the new Corvettes/XLR's with a pushbutton, as long as you've got the remote on you, it works. To make it work every time without issues is a little scary though.

            Anyway, good luck with whatever option you choose.


            How Much Horsepower Can I have And Still Go To Heaven?