While driving the key not detected message appeared three different times during a 50 mile trip. The message lasted approx. 30 seconds. Any answers. Thanks
The most popular answer is the rear hatch isn't closed properly and the (light)toggle switch is engaging over bumps or around turns, another possibility is the fob's battery is weak.
The 2010 does not have the slot in the dash, assuming the OP's profile is correct. You have to hold the fob up to the power button.
By any chance, you don't happen to have an "FOB" from another "Toyota" vehicle, in your pocket, do ya?.......been/there done/that.......FWIW
+1 for the FOB battery. Even though it still works intermittently there is a chance the voltage drop due to sitting in sunlight may trigger the warning.
Yup, it's most likely the FOB battery. It's now old enough. The other answers are also possible, but the FOB battery is now old enough to be nearly dead, and the continued "checking" of it while in the car is probably drawing it below the threshold of the "key not detected" message.