just a small fyi purchased prius new in feb 2007 now at 22,000 miles the spare keyfob still works, even tho it has been unused since feb, it still unlocks the doors and starts the car. i have read concerns about leaving the fob out of regular use on the prius and people wondering if after so many uses the car might forget about the unused fob, but mine still works
I think state-of-the-art code rolling systems are multi-channel, which means it can deal with multiple remotes (think of it as duplicate systems inside - each deals with one remote). Each channel handle a different code rolling sequence independently. For example, your Prius only needs to be dual-channel to deal with two remotes that came with your vehicles. Your spare remote will always be usable. Just from my understanding of this subject. Someone please correct me if I am wrong.
No worry. The rolling code system using a mathematical function to determine the next code when the button is pressed. Both the reciever and transmitter (fob) are synched to establish which code the reciever will expect next. But, in order to assure there isn't a problem if the user presses the fob button when away from the receiver, the reciever actually expects one of the next 100 codes. The algortihm generates over a million codes, so your chance of the reciever loosing track of your fob is extremely small unless you press your fob button over 100 times when away from the vehicle. The reciever is capable of learning and remembering 4 or 5 different fobs so you won't have to worry if one fob gets used 500 times and the other isn't.
This is correct, and is also the reason that each Prius supports a limited number of fobs (4). Otherwise you could use as many as you wanted, but they would all need to stay within the allowable number of codes. Tom
