SMac770

Past three years or so, the image would start fine but then go dark or turn into waviness or such as the car bounced over the driveway curb or such. Or it would start out messed up and then fix itself over a curb. Lately though, it's just always messed up. So I figured it was a something loose thing, and most sources seemed to imply a problem within the camera module or the connecting plugs. Thus I went replacing pieces expecting one to finally address the issue. I replaced all three parts on that path (camera module, blue gray cable with farka plugs, J772 control module) and still no good.

Pulling the green cable gave a different DTC code talking about video connection 1. Plus, if the problem was with that cable, why wouldn't I get a code from the J523 module rather than the J772 module? So I was not expecting an issue in that direction.

But turned out it was with the green cable, where it plugs into the J523 module behind the climate controls in the dash. Smacking the dash, I was getting the same results as bouncing over curbs and such. Pulled the CD changer and unplugged/replugged the green cable and now things are working as expected again.
Wasn't sure about putting a large video file on here, so posted it to youtube: youtu.be/xTSueIBlHfg

(note, 2010 and later with MMI 3G will have a J794 module in the dash rather than a J523 module, but they are interchangeable for the purpose of this topic).