SKS fob flashing light

We bought our 2005 Prius last month and have been driving it with no problems.


Both SKS fobs are losing their rubber buttons. I understand that the buttons (or the fob case) can be replaced without having to replace the entire fob or reprogram the SKS, but I haven't made the time to take care of that yet. Maybe next month.


In the meantime, one of the fobs stopped working-- classic symptoms of a dead battery. When I opened it up (thanks for the instructions!) the inside was corroded & filthy with rust & dirt. I cleaned the interior of the battery case with rubbing alcohol and a swab and removed the contact's corrosion with a pencil eraser. I left everything out to dry on the kitchen counter for a few minutes... well, actually a couple weeks. The fob's battery case looked like new when I inserted the replacement battery.


The fob works fine with the car, both in the dash and in my pocket. All three buttons have a solid "click" feel to them. However when I hung the fob on its hook in the garage, every minute or so it would flash and the Prius would beep. I guess that new battery has a great range. Sure enough, the owner's manual suggests keeping the fob at least five meters away from the car.


The fob is now about 10 meters away from the car, and the car isn't detecting it anymore. However the fob kept transmitting for a while. For the first few minutes it would flash about 20 times every minute or two. For about the next half-hour, it seemed to be activating itself once every 5-10 minutes by flashing about 20 times.


I thought it might have a stuck button, but pushing all three buttons (once each, once at a time) didn't seem to feel as though they were stuck.


Now the fob's been dark for over 10 minutes. Whew. It's the same feeling of relief when your baby finally goes to sleep. I was wondering if the fob was going to drain its battery trying to contact the car. But the "problem" seems to have solved itself.


Has anyone seen this behavior before? If I needed to get better flashing/timing data then I'd start all over again with removing the battery, but it looks like my immediate crisis has abated. In the meantime, if anyone can point me to a reference or a link describing the fob's flashing/timing behavior then I'll know what's going on when the other fob's battery dies...