431 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If 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.
SmartKey
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove the mechanical key1 
(page 426).
1Mechanical key
2Slide
3Battery compartment
Insert the mechanical key1 in direc-
tion of arrow in side opening.
Using mechanical key1,push gray 
slide 2 to unlatch battery compart-
ment 3.
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.iWhen replacing batteries, always re-
place both batteries.
The required replacement batteries are 
available at any Mercedes-Benz Cen-
ter.
 
432 Practical hintsReplacing SmartKey batteries
Pull battery compartment3 
(page 431) out of the housing in di-
rection of arrow.
Remove the batteries4 in direction of 
arrow.
4Battery
5Contact spring
Using a lint-free cloth, insert new 
batteries4 under the contact spring 
5 with the positive terminal (+) side 
facing up. 
Return battery compartment 3 
(page 431) into housing until it locks 
into place.
Slide mechanical key 1 (
page 431) 
back into the SmartKey.
Check the operation of the SmartKey.
SmartKey with KEYLESS-GO*
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove the mechanical key 
(page 426).
Insert the mechanical key1 
(page 431) in side opening and push 
grey slide2 (
page 431).
Battery compartment3 (
page 431) 
is unlatched.
Pull battery compartment3 
(page 431) out of the housing in di-
rection of arrow.1Battery
2Tilt battery up
3Mechanical key
Using mechanical key3 apply pres-
sure to position2.
Battery1 tilts up slightly.
Pull out batteries1 in direction of ar-
row.
Using a lint-free cloth, insert new bat-
teries with the positive terminal (+) side 
facing up. 
Return battery compartment3 
(page 431) into housing until it locks 
into place.