To replace a used MB TCU, the internal immobilizer data stored in the module must be virginized. They can only be installed in the vehicle by online programming or personalization (data transfer) via using the original manufacturer tool.
At present, only destructive operations on FBS4 (VGS4-0-NAG2) 7-speed TCM units through cutting or soldering to read or write the data. These procedures are complex and carry extremely high risk of module damage. It also require highly skilled technicians to operate. Any operational error may result in irreversible damage and significant financial loss.