There have been posts before about LCM fault causing Canbus issues & other ECU's to behave badly. Disconnect it forst and see if the other ECU's clear properly. Otherwise you need to work through all the faults.
L322 battery drain is often bonnet switch or heater blower resistor pack fault. Anything electrical that gets damp or water ingress can also cause issues.
- Bonnet switch fault stoped the BCM sleeping properly on a mates L322. It can be disconnected if I remember correctly, which also means the BCM thinks it's closed & you can then diagnose the drain issue with bonnet open.
- If heater blower pack is faulty the fans will run slowly after the car is switches off.
If it's not these or alternator, then you need to work through the fuses one at a time until the drain stops (
letting the BCM sleep each time), until you find the culprit.