Mercedes-Benz Key Specialist
Same-Day Service

For most Mercedes models through 2019, yes. The W204 and W205 C-Class, W212 and W213 E-Class, W221 and W222 S-Class, W164 and W166 GLE, and related platforms from roughly 1998 through 2019 are all serviceable on-site using Autel IM608, VVDI MB, and compatible EIS tools. We read the Electronic Ignition Switch, pull the security PIN, and pair new keys at your location without towing. Post-2020 models with FBS4 or FBS5 security require online Xentry server authentication that is only available through authorized channels, and we confirm your model year's requirements from the VIN before scheduling.

KEYLESS-GO is Mercedes-Benz's branded name for its passive proximity entry and push-button start system, first introduced on the 1999 S-Class W220. The fob communicates with antennas around the door handles and interior to detect your presence without any button press. Replacing or programming a KEYLESS-GO key requires syncing the new fob with the Electronic Ignition Switch module using professional tools that can read and write the EIS data. There is no owner self-programming method on any Mercedes model with this system.

This is the most common complaint on post-2015 KEYLESS-GO models including the C-Class, E-Class, and GLE. The most frequent causes in order of likelihood are a weak CR2025 or CR2032 fob battery, a weak 12-volt vehicle battery which is especially common in Southern California heat, radio frequency interference from nearby electronics, and less commonly a failed vehicle antenna or EIS module. Try the fob against the start button first. If both fobs fail simultaneously with fresh batteries, the issue is vehicle-side rather than the fobs. We diagnose and identify whether the problem is fob or vehicle during the service call.

Mercedes-Benz USA offers a key protection plan that covers replacement up to $800 per occurrence, which reflects the realistic dealer pricing range before that plan is applied. For complex all-keys-lost situations on newer platforms, dealer costs can exceed that threshold. Our pricing for Mercedes EIS-compatible programming on supported model years is significantly lower, covers the blank, cutting, and on-site programming in one visit, and requires no tow. See the pricing table above for exact figures by key type.

Yes. KEYLESS-GO equipped Mercedes models are susceptible to relay attacks, where two thieves use amplifiers to extend the fob signal from inside your home to your car in the driveway. Real documented thefts have been reported on the 2018 GLC and 2015 C63S AMG using this method. Mercedes introduced motion sensors in KEYLESS-GO fobs starting with the mid-2019 GLC facelift, which put the fob into sleep mode after about 20 seconds of inactivity and prevents relay capture. For pre-2019 models, double-pressing the lock button on the fob disables KEYLESS-GO broadcasting. A Faraday pouch for overnight storage eliminates the attack entirely.

EIS stands for Electronic Ignition Switch, and it is the module that Mercedes-Benz uses to store key data, verify transponders, and authorize the engine to start. Unlike most other brands where key data lives in the body control module, Mercedes centralizes this in the EIS, and programming any new key requires reading the EIS password first. The EIS password is extracted via OBD-II using tools like Autel IM608 or VVDI MB and is used to generate a key file that gets written to the new fob. If the EIS or the related Electronic Steering Lock module fails, the entire key programming process becomes more complex and may require module replacement before new keys can be paired.

Use the chrome release button on the fob end to slide out the hidden metal blade. Locate the door cylinder in the driver's door handle and unlock manually. To start: pull the start/stop button outward to reveal an ignition slot behind it, insert the blade, and the car can start from there on most E-Class and GLE models. On C-Class and GLA models, place the fob in the center console cupholder on the key symbol, press the brake, and push start. On S-Class models, the backup fob placement is in the center console marked space or dashboard slot depending on the chassis. The fob's RFID chip communicates passively without battery power once positioned correctly.