Mercedes-Benz Locksmith in Atlanta, GA: SmartKeys for FBS3 and FBS4 Cars

The immobilizer on a Mercedes-Benz goes by the name Drive Authorization System, DAS for short, and StarTuned, the carmaker's own technical magazine, says some kind of electronic immobilizer has been installed on its cars since 1992. Locksmiths and tool makers number the generations FBS3 and FBS4, and Mercedes' US dealer bulletin on replacement keys uses that same FBS4 label for the newest one. The third generation brought the SmartKey, which StarTuned credits with eliminating the mechanical tumblers in the ignition switch: the key slides into a slot in the dash called the electronic ignition switch, or EIS, and talks to it.

The 2012 C-Class coupe operator's manual shows how that slot behaves. The SmartKey turns through positions 0, 1, 2 and 3. A SmartKey belonging to another Mercedes turns just the same, yet the engine stays off. Pulling the SmartKey out locks the steering, and a mechanical key for the door is tucked inside the SmartKey, freed by a catch. Cars with KEYLESS-GO carry a removable Start/Stop button in the slot instead, and the 2015 C-Class manual adds that the button starts the engine only while the SmartKey is inside the car.

The fourth generation kept the shell. StarTuned says the DAS4 SmartKey looks like the DAS3 key while its electronics were updated, that DAS4 reaches the car by radio alone where DAS3 also used infrared, and that DAS4 is five control units on the vehicle network, the SmartKey (A8/1) and the EIS (N73) among them. Holding the key tells you nothing about its generation. The chassis does, and on a few cars so does an option code.

Mercedes' Star Bulletin S-B-80.57/62a, dated October 2014, names the FBS4 cars: every Model 205 (the C-Class from 2015), 217, 222 and 231; the 2013 Model 166, the ML, when it carries code 803; and the 2014 Models 207 and 212, the E-Class coupe, cabriolet and sedan, when they carry code 804. StarTuned dates the 166 to 2014 instead, so on that SUV the deciding item is the option code printed on the data card rather than the model year. The W204 C-Class of 2008 to 2014 sits on no FBS4 list: it is an FBS3 car.

That split decides the visit. On FBS3, a new SmartKey is programmed beside the car with equipment that reads the electronic ignition switch. On FBS4, StarTuned explains, keys are programmed in XENTRY, Mercedes' dealer diagnostic system, under rights held by select dealer staff. The car is first registered with the Daimler server using a key that works, and the new key must be programmed within 72 hours. With no working key the car cannot be registered, and the dealer turns to a fallback process in which Mercedes performs the registration after paperwork.

For independent locksmiths, NASTF announced a route in August 2022: a NASTF VSP orders a DAS4 key, pre-programmed for one VIN, through a Mercedes-Benz dealership it chooses, and the dealer places the order within 72 hours. 4Keys Locksmith holds the XENTRY subscription that route asks for and orders FBS4 keys built for the VIN through it, so the key that arrives is an original key made by Mercedes for your car. The Mercedes key equipment in the van also includes a CGDI programmer, which is aftermarket key-programming equipment, not dealer software. Mercedes' Star Bulletin caps the count on FBS4 cars at the two factory keys plus six more, eight in all, and lets any one key be replaced a maximum of two times. Whether a locksmith reaches that level on other makes is covered under the dealer software question.

Vans leave Brookhaven for every part of Metro Atlanta. Among the Georgia pages that show the service area are Buckhead, Sandy Springs, Roswell, Alpharetta and Smyrna, and the same dispatch covers the rest of the metro.

The technician works on the Mercedes wherever it is parked: a driveway at home, a gated apartment lot, an office or hospital parking deck, a workplace lot. For a gate, read out the code when you call or wait for the van at the entrance; for a deck, give the level and the row, since the car is worked on in its space.

The van that programs a SmartKey also carries lock hardware. At home that means lockouts, rekeying after a move, new deadbolts and smart locks, all described under residential locksmith service and the Georgia residential locksmith page. For a business it means rekeys when staff change, master keying, card readers and keypads, and panic hardware, set out under commercial locksmith service and the Georgia commercial locksmith page. One call can cover the car and the doors.