[Zebster]

The CEM may well be fine, water getting into vehicle CANbus/comms connectors will cause the issues you have. My V60 had a variety of 'interesting' issues like yours (occasionally dead dash and infotainment displays, multiple warnings and alarms, loss of electric windows and central locking, etc) because of a leaking rear washer pipe dripping onto under-dash connectors. A pipe repair followed by a careful drying of the affected connectors (plus an application of switch grease to the connector pins) brought about a full repair with apparently no permanent harm caused.