In severe cases, if the immobilizer or BCM is involved, the car may fail to start.
Adding a new component (like a different radio or display) that wasn't properly "paired" or programmed to the vehicle's CAN-bus. opel u2102-00
U2102-00 Definition: CAN Bus Data Mismatch / Configuration Mismatch / Software Incompatibility Severity: High (Can lead to no-start conditions or significant electrical failure) Systems Affected: BCM (Body Control Module), ECM (Engine Control Module), IPC (Instrument Panel Cluster) In severe cases, if the immobilizer or BCM
CAN BUS missing communication | Vauxhall Owners Network Forum In severe cases
Here’s a useful, technician-focused write-up for .