Installed my NEX4000 about 3 months ago with a rear camera.  Everything was working fine up until about a week ago.  Ever since then whenever I put the car in reverse the unit does not switch to the rear camera view.  I've verified the camera works with the "camera view" setting.  Any suggestions?

Verify a change in voltage on the violet/white wire when shift lever is placed in Reverse.

Of course there's the obvious... make sure all your settings haven't change.

Bizarre. I'd guess the reverse sensing wire came loose. Also, check the setting re ground vs battery and make sure you didn't accidentally change. Good luck.

is your reverse light blown out?

is your reverse light blown out?

Vehicles typically have two... and both would have to be blown... typically.  Blown fuse is also possible.

First make sure the setting is appropriate (power, or ground), and confirm you're getting the requisite voltage, or lack thereof, when the vehicle is in reverse. sounds like connection or settings issue.

Update....It started working today and I didn't change anything.  Weird.

Update....and now it's not working again...ugh..

it seem to me you have problem either power or ground, where did you get power for the camera? I run power from the back of the tail light to HU wire, power camera is hook to HU key on wire.

I got the same issue. I have 4000NEX.  Usually, when i leave to work in the morning, it works when i reverse. Then there after, it doesn't.   

For me, when I reverse, the screen switches to backup screen with the writing (caution, blah blah...), however, the screen is black. And it's intermittent. Once in a while it works, then it doesn't. 

My wiring: I have the reverse signal wire connected to the harness located below the steering column. For the camera power, I have connected to the ACC power lead.  Setting: Battery

Anything i'm doing wrong? I've noticed this issue happened after I installed the bypass kit (3 wire).