398 Practical hintsReplacing SmartKey batteriesIf the batteries in the SmartKey are dis-
charged, the vehicle can no longer be 
locked or unlocked. It is recommended to 
have the batteries replaced at an autho-
rized Mercedes-Benz Center.Batteries contain materials that can harm 
the environment if disposed of improperly. 
Recycling of batteries is the preferred 
method of disposal. Many states require 
sellers of batteries to accept old batteries 
for recycling.Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help 
immediately.
iWhen inserting the batteries, make 
sure they are clean and free of lint.
When replacing batteries, always re-
place both batteries.
The required replacement batteries are 
available at any Mercedes-Benz 
Center. 
399 Practical hints
Replacing SmartKey batteries
SmartKey
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove mechanical key1 
(page 394).
1Mechanical key
2Slide
3Battery compartment
Insert mechanical key1 in direction 
of arrow in side opening.
Using mechanical key1, push gray 
slide2 to unlatch battery 
compartment3.
Pull battery compartment3 out of the 
housing in direction of arrow.
Remove the discharged batteries in di-
rection of arrow.
4Battery
5Contact spring
Using a lint-free cloth, insert new 
batteries4 under contact spring5 
with the positive terminal (+) facing up.
Return battery compartment2 into 
the housing until it locks into place.
Slide mechanical key1 back into the 
SmartKey.
Check the operation of the SmartKey.