loosing key number!

from what i've learned. if you don't have more than two keys, or the little keychain, they have to deprogram your car and reprogram new keys. i heard this cost hundreds to do.

if you have two key fobs they may be able to go in while keeping those two keys in the system... and add another. It's been a while since this has been talked about.

 

I believe the plate with the key number is just the code that describes the depths of the cuts in the mechanical key that is stored in the fob. That key can be copied just like any other car or house key by using a existing key as a template. Howerver, if you lose the key, but had the plate with the cut depths on it, then the dealer could make a new key without needing a existing key to copy.

Here's a tip. I leave the plates with the codes on them on the key rack in my house, but I programmed the numbers off those plates into my cell phone. So if I'm on vacation and lose the key, as long as I have my cell phone, I can still provide the number to a dealer.

 

This is correct. The process of cutting a key from the depth numbers is called code cutting, and is used to make a nearly perfect replacement key. With mechanical keys, after you make a copy of a copy of a copy and so forth, things get a little sloppy.

As for the other poster, the SKS allows multiple key fobs to be associated with one Prius. I believe the magic number is four. The car is programmed to use the fobs, not the other way around. The mechanical key number is in no way related to the SKS fob, other than describing the little mechanical key contained inside. Replacing a lost fob is expensive. Try not to lose them.

Tom