My MFD2 will not communicate with the car anymore

[kiddfrost]

Hi,
I disconnected my mfd2 today to run a cable for when I get an RNS but when I put it all back together the car doesn’t seem to recognise its there anymore. The unit seems to work fine on its own but the buttons on the mfsw don't control it anymore, no more audio menu in the highline, no more satnav display in the highline and it doesn’t turn off anymore when you turn the ignition off.  VCDS says it can’t communicate with the radio.
I’ve re-seated all the connections on the back of the unit but still no joy.

Any ideas anyone please?

[alexperkins]

Sounds like you have disturbed the Can HI-Lo cables

What cable did you put in?

[kiddfrost]

Sounds like you have disturbed the Can HI-Lo cables

What cable did you put in?

I managed to sort it a few days ago thanks but you're pretty much bang on. I installed a FIS+ box a while ago on the the CAN and it turned out to be the FIS+ cable. I thought there was no way it could be that because I went nowhere near the CAN. All I did was disconnect the head unit and run an MDI cable in which is not connected to anything so I was convinced it had something to do with unplugging the head unit. It was really strange it turned out to be that cable.