I'm hoping the forum can help. I'm having zero success with my dealer, who installed a US Spec trailer hitch on my 2023 C40. The installation included the hitch, wiring harness, control unit. When i drove away I immediately noticed that I had no park assist, no rear auto braking, and no rear fog lights. All working prior to the installation. The rear camera works. The dealer says the issue is something with Volvo's software programming, but I suspect a connector is not connected, or a wire was damaged. They said they needed Volvo to give them guidance, and after six weeks of attempting to work with them they are now ghosting me.

Might any of you have insight on how to troubleshoot this issue? Anyone have a wiring diagram for this area of the car?

Many thanks!

Groovin