Parkassist code 0431 - rear display unit fault

[iamtheari]

I had a dealership do a couple things to my 2004 Cayenne Turbo as a Christmas gift to myself. One was to repair the parking sensors. One sensor in the front had to be replaced. But all rear sensors seemed to work, despite the red warning lights instead of actual measurements being displayed.

The code came up as 0431, which evidently means that the rear display unit is the problem. I also have a sagging front headliner. So the question is whether I can remove the display unit, check the wiring connections that are probably just loose, and spray in enough adhesive to keep the headliner in its place through the display unit opening.

Or if I can at least take down the display unit to check the wiring without pulling the entire headliner.

Anyone with experience in this area? Thanks.