I have limited information on it but you have the main motherboard on top of the battery, and just behind the lense on the device there is a second smaller one which controls the camera.
We just pushed it forward and it came on
Scratch all that , we managed to fix it.
The motherboard that the actual camera is connected to had a poor connection that when pushed forward made the camera work.
And the fault code (companion camera input failure) has disappeared.
Sorry I have no idea how it connects to the car but I doubt it's on the canbus., although it may send the images over the canbus. I suspect it uses RF but I've never been able to find any info on it.
What's the canbus error you're trying to fix?
Which was why I asked what menu he was looking at.
EGR would be closed on idle though.
Maybe the fuel pump is the FBH pump, maybe the Glow plug is for the FBH.
And yes they have an auxiliary pump for when the FBH is running.
J