Mercedes cl start up faults

OK so, I had an issue with my battery running flat, in the end it wouldn't hold a charge so I bought a new one.
Before I bought a new one I started getting problems and hoped this would sort things out.
I'd say every 1 out of 3 starts I get a barrage of faults appear and the car won't come out of park.
I get ABC (active body control), ESP and BAS (brake Assist) and distronic faults, on top of this the indicators stop working, the auto headlights stop working among other non essential bits.
Some times it works fine and there are no faults.
Alot of the fault codes point to something called a N73 module and refure to the CAN

Any help would be appreciated because I'm absolutely lost