Not having a clue as to what system is failing I will state a few things about CAN and batteries.
CAN is the network that runs between controllers passing pertinent data. During cranking battery voltage can drop below 9v and still start the engine. As battery voltage drops below 9v certain controllers turn off. This can leave the other controllers not recieving pertinent info and they start using mapped programming as a safety protocol. some systems won't come back until reset. some just record the fact that the event happened.
Consistant lack of CAN data from one controller probably indicates a controller/CAN problem. Various CAN messages and a low voltage message or two is more likely a battery or charging system problem
Bosch Master, ASE Master, L1
33 years MB technician