Mercedes Key Fob Replacement

A Mercedes fob that has stopped working is not always a fob that needs replacing, and on this make the difference in cost between the two is significant enough to be worth checking properly.

Check these first

• Battery — Mercedes fobs use batteries that are easy to change and easy to forget
• One key or both — if both stopped, the fault is in the car, not the keys
• Water damage — these fobs are carried daily and are not built for weather
• The emergency blade — hidden inside the fob body, it opens the door but will not start the car

If only one of your two keys has failed, that key is the problem. If neither works, look at the vehicle before spending anything on keys.

Replacing a lost fob

Replacing a lost Mercedes key is not the same as adding a spare, because the missing key should also be removed from the vehicle where the system allows it. If your keys were stolen rather than mislaid, that step matters — say which it was when you call.

Which generation you have still decides things

As with all Mercedes key work, the model year determines what is possible. Adding a fob to an older EIS or EZS car is straightforward for us. On later FBS4 vehicles it may not be possible independently at all. We check before dispatching, not after arriving.

My Mercedes key stopped working. Is it the key or the car?

If your other key still works, the fault is in the dead key. If both have stopped, the problem is in the vehicle and replacing keys will not fix it.

Is there a hidden key inside the fob?

Yes, most Mercedes fobs contain a mechanical blade that releases from the body. It will open the door but will not start the engine.

Can you add a spare Mercedes key?

On the generations we service, yes, and it is considerably cheaper and quicker than replacing keys after they are all lost.