The last several times I've gone for gas, the car won't recognize the smart key after fill up, either in or out of the slot. It does not recognize either of my 2 smart keys. I have changed the batteries in both keys. I am able to lock/unlock doors, but not start the car. The red light on the dash indicates there is no key. Dealer cannot find the problem. Eventually the car does start after some time (5 to 20 minutes) and I have not been able to identify what changes to make it so.
Do you keep your cellphone next to your fob in your purse? It's been known that cellphones can interfere with the SKS signal. Try holding the fob right next to the Start button. That will work even when the fob battery is dead or removed. SCH-I535
We've seen that issue occur with the Concours 1400 MC at certain gas pumps due to rf interference. Some pumps use rf for swiping fobs/cards as payment. But with our bikes, you can at least push them away from the pump to enable them to start.
I always get gas at the same station. I'm going to try another station next. Last time I filled up I was able to dock one key in the dashboard to start it. The other key wouldn't work. Thanks, Sparky! It is nerve wracking to not know if the car will start or not.
I'm no RF engineer but I've built /mod'd transceivers operating between a few khz up past 2ghz. AFAIK, the low power/Bluetooth bandwidth used as card readers can only receive/transmit out to a range of 4"-5" or less - otherwise your rfid credit cards could be cloned/stolen too easily. Even the fluorescent lights built into gas pumps radiate stray RF a lot lot farther out than that. I'd find another source to be the problem - such as the ECU that controls the Prius' receivers. .
At my last visit to the gas station, neither key would start the car, but one fob worked in the dash and the other didn't. Next I'm going to try a different gas station and see what happens.