Recently, on our 05 Pruis, the alarm has been going off randomly, even with the door unlocked, as if the panic button has been pressed (nothing is in the sunglass holder). Also, the lock/unlock button on the fob does not work and the red light does not come on, even after replacing the fob battery. Interestingly enough, the car still recognizes the key and will unlock the door if I grab the handle and will let us drive without the key plugged in? I think the fob is shorted out somehow and we need to get a new fob and have it programmed by the dealer. This is our only fob as we bought the car used. In the meantime, will removing the battery from the fob stop the random alarms and still allow us to access the car? Any other suggestions/ tips?
The first suspect when wierd things happen is the 12V battery. People with 2004s have been having such problems for at least a year, so it looks like it has come time for the 2005s. If you only have one keyfob, you're on really thin ice. To protect against a $500+ service visit when you lose the last key, get another keyfob as soon as possible. A cheap ($50?) one off eBay that you program yourself to work in the keyslot is adequate insurance. Full function (proximity, buttons) costs $200 new, + $50 service fee. Double these numbers for particularly greedy dealers.
