Kirk,
I'm guessing since I don't have the JDM but ...
I doubt there is a protective cover over the camera. I'm guessing that there is probably not even a relay to power the camera. The camera probably receives power directly from the reverse lights.
The first step you should take is to check all of your fuses. Also check to make sure that your reverse lights are working. It's entirely possible that the reverse switch (turns on reverse lights) in the tranny is not functioning properly.
Even though you may not have a CEL, have the codes read. An error code could be stored that does not trigger the CEL (it happened on my TLC).
Tom
BTW, the electrical manual is in the download section. I think the reverse light section starts on page 112.