Dont know if this info has been dropped here at TW or not, just thought I would share my experience.
I have a 2010 regular cab that was prewired for the backup camera but did not come the camera module or the rearview mirror monitor. I recently purchased the camera module from someone here on TW and hooked it up to my Pioneer AVIC F700bt HU. Below is a pic of the camera harness location along with the pinouts to the camera.
BLACK = Camera 12v +
SHEILD = Camera 12v -
RED = Camera Video +
WHITE = Camera Video -
I don't know WHAT Toyota was thinking when they engineered the color code for this, but it is what it is.....
Now for the harness itself, the male socket goes to the camera and the female I assume goes up to where the rear view mirror monitor plugs in. I also found the the 12v power legs of the harness are not hot, I guess they get power from the rearview mirror? So I supplied power to this circuit from the HU along with my video feed up to the HU.
Hope this helps someone!!