Keyless FOB technology?

Discussion in 'Electrical' started by Breeze3at, Nov 26, 2010.

  1. Breeze3at

    Breeze3at Well-Known Member

    While in a turkey induced semi-coma last evening, I got to wondering about how the keyless proximity FOB works. Does the FOB constantly transmit a signal, or does the ECM constantly transmit a signal that activates the FOB when it is in range? What kind of signals are involved (IR, radio, microwave), and what is actually "switched on" in the ECM to allow starting? Will the FOB battery go dead quicker if it is always kept close to the bike? Evidently as I age, the tryptophan in turkey, affects my brain like THC did in the 60's. :D
  2. dbmg

    dbmg Guest

    Its not the turkey Breeze3at its the 5 pounds of food, pumpkin pie and the spirits drank with dinner.
    If the remotes are like car fobs it transmits a radio frequency (mhz?) which the module verifies compatability and will allow the system to wake up.
  3. ProF

    ProF Junior Member

    It's a good thing that once started, the bike won't shut off if the key fob is moved away from the bike.

    Can you imagine being on a crowded freeway, hitting a bump, and having the key fob fly out of your pocket?
  4. johnkarlfl

    johnkarlfl Active Member

    I didn't know that I will have to try it
  5. RibEye

    RibEye Junior Member

    My guess is that when an event occurs, bump, tilt, etc, the alarm pings the fob. If the fob responds, the alarm is inhibited. If the fob does not respond, the alarm goes off and the ignition is inhibited. The signal is very limited in power, so the fob has to be within 20ft or so.

    My system has 3 different RF emissions: microwave cloud around the alarm to detect proximity, fob pings on event, and status pings at a distance of around 1/2 mile if the line of sight is clear. Mine is an aftermarket system. If an event occurs, the ignition is disabled, and my fob is notified of the event, causing it to vibrate and display an event icon. If hijacked, I can kill the scooter's ignition from up to 1/2 mile away.

    Rich P
  6. pru7536

    pru7536 Active Member

    ProF, like johnkarlfl. I had no idea the bike wouldn’t shut off if the fob was not close to the bike. I have periodically worried about starting the bike in my garage where my jacket, with the key fob in my pocket stays, then taking a quick ride without putting the jacket on and heading to the corner store. So far, I always remembered to get the key and fob, but I have come close a couple of times. As inquiring minds want to know, I just went and cranked the bike up, rode it 50 feet with no key fob and turned it off. Needless to say it wouldn’t start, but now I know. DON’T FORGET THE FOB! My old ’07 would start if the fob was within about 20 feet; the ’10 won’t start unless the fob is within less than six feet. It’s a great system unless you ride off without the fob. It may be a good time to put a new personal identification number in and carry the card that tells ya how to override the security system, ‘cause I know I’m going to forget the fob now.
  7. Breeze3at

    Breeze3at Well-Known Member

    This quote from the above tips (and owners manual) answers one of my questions.

    "The system can not detect whether the fob is in range at any other time.
    Because the system is not communicating with the fob all the time, current draw is lower, and battery life is extended."

    At home, I have been keeping the FOB in my windshield bag so the lights don't flash every time I touch the bike. I guess I'm putting a draw on one of the batterys, so I'm gonna move it away from the bike.
  8. dbmg

    dbmg Guest

    Had a customer send friend to shop to get Harley serviced from 50 miles away. Owner was standing next to friend and bike started. Customer did not give friend fob so guess what would not start after friend shut bike off at shop. Friend did not have code with him so he had to wait for owner to bring fob to ride bike home.
  9. Grillfish

    Grillfish Junior Member

    One item, I've read that another rider could not start his bike even with his FOB in his pocket. He had to use his code and thinking about where he parked, it was under high power transmission lines. Could those lines interupt the signal enough for the FOB not to work? Just curious.
  10. gator508

    gator508 Well-Known Member

    Breeze, you are telling on yourself,, LOL

    Works on a radio signal per the HD bulletin. An interesting thing..was trailering the bike and noticed the directional signals were flashing all the time, alarm going off, pulled over and put the fob in the saddle bags, I had thought the range was greater than that.