Starting Your Mercedes-Benz
To start a Mercedes-Benz that uses the tapered SmartKey style, the engine Start / Stop ignition button must be removed. It appears to ‘float’ above the dashboard and is easily pulled away from the ignition lock. Insert the tapered end of the KEYLESS-GO key in the ignition lock and turn it to start and operate old school style.
Beginning in 2017, the ignition lock in AMG roadsters and coupes is found at the back of the center console storage area, as shown in the image. Insert the tapered key fob into the ignition lock and turn it to start and operate old school style.
Models using the new, rounded SmartKey style, require that the SmartKey be placed in a back up location or slot. Do NOT attempt to remove the Start / Stop ignition button!
The slot is found just in front of the cup holders on the center console. It is marked by the image of a key with lines radiating from it, as shown in the image. Note that the slot is smaller and to one side in E-Class models, but is marked in the same way.
Slide the SmartKey into the slot with its buttons up and start as normal. The car will recognize the key fob even if its internal battery is dead.
Note: If you have made an attempt to start the vehicle without success, there may be residual pressure in the brake system and a new warning light may appear (left) or text message to Step on the Brake. Press the brake pedal very, very hard when trying to start the vehicle again to be sure that the release switch behind the pedal is engaged. Check out this page for more!
Click here for video help specific to Mercedes models and key fobs.
* Keep these instructions with you in our Dead Key FOB App. Search “Dead Key FOB” at your device’s store or click here.