I have the Pioneer avic 5100NEX.  I messed with my back up camera settings and now even in Drive my camera stays on or I get the black screen that says "Caution images may appear reversed..."  I know I need to change the settings back, but I cannot get into them because the screen won't allow me to press any buttons.  I have tried the reset button.  I keep reading about pressing and holding mute, but I do not have a mute button.   My mute is on my touch screen.  How can I get the back up camera off when I cant get to my settings?

I have the Pioneer avic 5100NEX.  I messed with my back up camera settings and now even in Drive my camera stays on or I get the black screen that says "Caution images may appear reversed..."  I know I need to change the settings back, but I cannot get into them because the screen won't allow me to press any buttons.  I have tried the reset button.  I keep reading about pressing and holding mute, but I do not have a mute button.   My mute is on my touch screen.  How can I get the back up camera off when I cant get to my settings?

You probably set it to turn on with ground rather than battery, or you connected your reverse wire to the wrong lead in your car.  There are a few ways to address this situation. 

1. Did you set your trigger for battery rather than ground? (Or vice versa?) If so , your camera should turn off when you are in reverse. Go into reverse but keep your foot on the break. Your cam should turn off and then you can change your trigger from battery to ground. 

2. Did you connect the backup wire to the wrong lead? If you connected it to ground, constant 12v, or ignition, you're going to need to disconnect that wire  so you can have the car turned on so you can  get to the backup camera settings and turn it off.

Try putting the car in reverse. Then try change the setting. It that doesnt work pull out the radio and play with the purple/white wire and putting in to ground see that change then try connect to red wire on radio. And see if you can change the settings.

I had the system professionally installed a few years ago.  I accidentally bumped something and my back up camera quit coming on so I went into settings and messed with a bunch of settings until it started working again.  That being said...I know I changed the trigger, but to what idk.

I tried your suggestion of putting it in reverse with my foot on the brake and the camera still turned on.