Backup camera stayed on while in drive? Knock on start up?

Welcome to PriusChat!
I've noticed (in my 2009 Gen II) that if I'm reversing (RV camera "ON", BEEP! BEEP! BEEP! etc.) the audio controls don't seem to work, but I've always considered it a feature rather than a bug, albeit a demostration of sloppy QA/Usability procedures at Toyota (…are you reading this Akio Toyoda?), but to be honest, I've always considered guiding the car when reversing to be far, far more important than fiddling with the audio, but that's just me! )

 

the knock is just a cold soak detonation. try not to shut it down before the engine is done warming up.
the back up cam is unusual. maybe just a glitch. i'd keep my eye on it. could also be a 12v issue, if it continues.

 

This makes me laugh thinking of all the Gen2 owners who paid big money for "hacks" to allow the camera to stay on in "drive" or being able to enter stuff into the nav while the car is in motion.

 

Next time the rear camera stays on again, you need to enter the diagnostic mode and check if the radio is receiving the reverse signal. If there's a reverse signal, then there's something wrong with the reverse gear switch that's feeding reverse signal to the radio. If there's no reverse signal, then there's something wrong with the radio.