The answer is only dealer can add FBS4 keys. VVDI MB tool V5.0.2 can disable FBS4 key, CGDI MB can read FBS4 keys.
1. Since VVDI MB V5.0.1, it adds FBS4 disable key function(Special function->FBS4 disable key)- Support
2. CGDI MB can read FBS4 keys:
CGDI can read FBS4 keys and knows if it’s in a working status or if the key is damaged;
That is CGDI can’t make calculation for FBS4 . Only Read to know the status.
FBS4 applicable models: April 2013 to Present, Model W212; July 2013 to Present, Models 166, 207, V212; September 2014 to Present, Model 218; November 2014 to Present, Models 117, 156; April 2015 to Present, Model 172; MY-AII, Models 205, 217, 218, 222, 231.
MY2013, Model 166 with Code 803, Models 207 and 212 with Code 804.
Besides, you can check SA Codes on vehicle data card or use any suitable online vin decoder to see SA codes related to your vin. You are looking for the presence of SA code 803 or 804, depending on the Model this means vehicle is FBS4 related.