I went to a local shop and parked the Prius. It would not lock. I figure that the battery in the key fob is going flat so I get in the car and drive back home which is only about 1.5 km. I get home, pull into the garage and test the key fob remote. It's working fine. I then try to find the spare key fob. It's not in its' usual place. So I panic and turn the house upside down looking for it. I eventually found it in a weird place...Don't ask. Getting back to my story, I drive back to the same shop and park in the same spot. Lock the Prius with the remote. Just to check, I press "unlock" on the remote....nothing. Ok, no biggie I figure I've got the small backup key inside the fob. First though I go to a camera shop and buy a new battery for the key fob remote. Try to install the battery in the shop, but they don't have the right screwdriver. Back at the Prius I unlock the door with the little spare key. The alarm goes off. I put the key fob in its' slot and press Start. Car switches on and alarm stops blaring. I go back home...again. Back home I change the battery in the remote and all is well again. Oi! I have a theory as to why the remote worked in my garage and not in the parking lot. It could be that the parking lot is much more noisy in the RF part of the spectrum where the remote works than my garage. A "weak" remote might have enough S/N ratio in a RF quiet garage to operate the car, but not in a RF noisy parking lot. Comments? Has this happened to you?
There have been cases where RF interference has kept a key fob from working, so your theory could be correct. Simply having a cell phone in the same pocket can be enough to do it. Tom
I know my Treo 680 likes to interfere w/ my key fob. If the phone and fob are in the same pocket and I try to lock the door with that button, the door won't lock. If my key fob and phone are in the same place in the car while it's running (usually the cup holder), the key-missing-light will turn on. cheers, andrew
In my country we´re used to radio-interferences, specially in big cities where Police and escort units use to be very cautious and "clean" electronically a possible radio-powered bomb. Sometimes it's enough a cell-phone to drive an attack. Most of the cars, not only PRIUSes, go stuck when next to a police station or a politician headquarters (escorts arround). Fortunatly most of the cars can be opened with an alternate mechanical key.
The owners manual talks about interference and the FOB with cell phones... good read for questions like this..
We just started to experience the same problem about a week ago, but only in front of our own house! A second priusowner has verified, and he is experiencing the same issues when parked in front of our house. We haven't gotten any new RF-equipment for months, so that can't be it. Turning of my wifi AP didn't help either. It could of course be one of the neighbours, I guess... Which is more likely to interfere? cell phones, or wifi? Who knows which frequency range the fobs use?