rwheller@gmail

The backup camera on 2016 W212 E350 went intermittent, then seemed to fail more than it came on. Since the vehicle is under origianal warranty, I took it to the dealer for repair. Dealer replaced the backup camera unit. It failed the QA/QC test drive. Dealer replaced applied all the software updates. It failed QA/QC test drive. Dealer replaced the wiring harness for camera. Video is displayed, but when the trunk lid is raised the camera image goes black. Tomorrow the vehicle will have been at dealer for 4 weeks. I have a loaner, but I only get 75 miles / day and cannot leave the "city." Any ideas?

- Robert

Mud

Wire harness for camera is at rear of trunk, maybe check main harness extending into trunk. May be an issue with a break that's highlighted when bending (opening trunk). Seems that dealer should know to look at this section too?

rwheller@gmail

Thanks Mud. I appreciate you taking time to reply. Like you, I would think that any place that wires bend would be inspected first. Especially when the screen goes black when the trunk is opened. It is hard to know what the servicer technicians have done, where they have looked, etc. when there is a service advisor between me and the techs actually working on the car. It almost seems like there might be a tight wiring harness that pulls apart when the trunk is opened breaking the connection -- or a signal that is shorting to ground when the trunk is opened. Its four weeks today and I think it is time to call the service manager.

Mud

You may want to consider buying an inexpensive WIS/EPC cd set off eBay, I use mine frequently. Includes complete wiring diagrams with connectors and modules identified. I do similar investigation when needed, verify connector pin readings, especially if I'm looking for reference voltage.
https://mbworld.org/forums/e-class-w...-packages.html

rwheller@gmail

UPDATE: after 4.5 weeks of car at the dealer -- under warranty, with a GLC 300 loaner, the technician found a issue with the coaxial cable in the main wiring harness from the head unit to the rear wiring harness. The replacement done under warranty required removal of seats, carpet, etc. from interior. Glad to have my E350 back.

I did buy the WIS/EPC cd set from eBay. I have not used it yet.