Hello everyone, everything in car works except the way to start the car with a dead key fob where you put key up to the start button to start it. The fob battery dies every week. Can't communicate with theft deterant ecu, but there are no codes for it, and code B2784 is in the key ecu, so that's weird how everything works car starts fine with a battery in key fob but need to have more than a couple batteries in case it dies. Now the push button coil code B2784 is for open or shorted coil, I got that and will test wires to it for signal and replace button if wiring are good, but my head scratching is why I have no comms to key ecu and car starts fine? All functions including proximity and door handles work 100%. Thank you. As far as I know the car was not flooded and this issue started out of nowhere about 3 months ago and I can't confirm comms with theft deterant issue started time. Fuse 3 on engine bay for theft deterant is blank, no fuse and no wires to it.
Wow that fuse is older is blank. Somebody's messed with that car and it could be a snaker fingering out. What's wrong. Once people screw around with the electronics on those things all bets are off. You would have to find some Prius pro seen something like that before to try to pinpoint it down. Otherwise you're paying somebody 200 bucks an hour just to screw around and try to find out what's wrong. So if you can find somebody you really knows how to work on Priuses ask him when his check out for you is for that problem
Thank you very much for your suggestion scotty.