I accidentally placed a heavy object on my key fob at home. It must have been there for more than five minutes before I noticed the little light flashing on the fob.

Since then I have not been able to lock or unlock the car using the fob or set or reset the alarm or immobiliser, although the light still flashes on the fob when I press it. I have replaced the battery, but still no joy.

My assumption is that it has lost synch with the car, and my plan is to get it sorted when I take the car in for next service as I have a workaround (use the key and a manual alarm reset) - this is what the manual recommends.

But is there a way to resynch the key myself?

Update: This is a specialist import 2006 Forester STi with a CAT 5 immobiliser. And I have discovered it is a Cobra fob.

  • 1
    Is it possible the battery is simply low? It may have been continuously transmitting when the button was held down. Does the manual say anything useful? What model and year? Dec 16, 2014 at 12:02
  • I would think a new battery might be in order as well. Remember that the fob is tied to the car, not the other way around. This means the fob has a transponder which is loaded into the car's body control module memory. The fob is just fat-dumb-and-happy (is a dumb device). The car will either recognize the fob or not. As long as the fob is able to transmit, the car should recognize it. Dec 16, 2014 at 12:10

1 Answer 1


It turns out the way to resynch a Cobra key fob is to hold both buttons down for about 6-8 seconds, or until the flashing lights stop flashing. You then release the buttons, and press each of them once.

Update: It turns out there is even a Cobra Car Tech YouTube channel, and they have a video showing what I have described above.

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