2017 V90 Reverse camera

[Sir0cco]

You have most likely installed wrong camera - the one from newer models.
It works like this:
V90 2017 and XC90 2015-2017 have old type of IHU (radio/navi) unit - it does not support direct connection to camera.
In those years - you need a special module which is plugged between IHU and Camera (WAM - Wide angle module - parking cameras)

I am curious, in the -2017 models, have you found if the WAM hardware is the same between rear-only and 360 cam equipped models?

I cannot confirm 100% but I am 99% sure that it is the case.
Why?

Looking at the used units - some have 3 plugs butchered by car-part butchers (1 camera + 1 IHU plug) , some have full 5 plugs (4 cameras + 1cable to IHU)
Interestingly when you read the label - the SW and HW version on both are exactly the same.
So it seems the unit can do both and responds accordingly to the request sent by the car - either backup or 360 view.

But my assumption is that the unit needs to be paired with the car.
Thats why a WAM reload is needed - as stated in the official VOLVO backup camera retrofit installation manual