I've got a real problem with my keyfob alarm in my '09 Prius. It goes off with the slightest touch many times. This morning, it went off twice, just dropping the keyfob on the bed, from a height of 4-6". Once it starts, the ONLY way to stop it is to run out to the vehicle, and start it. Pressing the alarm button doesn't do it, opening/unlocking the door doesn't do it. Turning ACC on doesn't do it - MUST start the car is the only way it stops. I'm really tired of this. How can I disable the keyfob alarm? Battery has been replaced in the keyfob (both), etc.
Possibly something loose inside of the fob, or maybe some dirt. Just swap fobs rather that try to disable an alarm.
Turn the switch off that is under the steering column and see if that shuts it up. Have you changed fob battery? It may be a damaged fob as well? Very unusual problem! H
The rubber that returns the black contact may be weakened or cracked. Take the FOB apart and pull it out to inspect it. You can clean the rubber and the PC board with isopropyl alcohol mixed with water 50/50 or lens cleaning fluid. If that doesn't help try electrical tape over the button. It may hold it up a bit. I'd just switch FOBs if you have another that hasn't been used much. They DO wear out eventually.
