When replacing a used Mercedes-Benz TCU, the internal immobilizer data must be erased before installation. Only after virginization can the unit be installed and programmed online or undergo personalization transfer by using the original diagnostic tool.

At present, the market only allows destructive operations on FBS4 (VGS4-0-NAG2) 7-speed TCM units through cutting or soldering.These procedures are complex and carry extremely high risk of module damage. They also require highly skilled technicians. Any operational error may result in irreversible damage and significant financial loss.