107 Controls in detail
Locking and unlocking
Unlocking and opening the trunk
You can unlock and open the trunk sepa-
rately.
A minimum height clearance of 5.71 ft 
(1.74 m) is required to open the trunk lid.
Press and hold button Š until trunk 
unlocks and begins to open.
The trunk can also be opened from its in-
side in an emergency, see “Trunk emer-
gency release” (
page 116).Checking the batteries in the SmartKey 
or SmartKey with KEYLESS-GO*
Press button‹orŒ.
Battery check lamp (
page 98) or 
(
page 102) comes on briefly to indi-
cate that the SmartKey or SmartKey 
with KEYLESS-GO batteries are in or-
der.Loss of the SmartKey or SmartKey with 
KEYLESS-GO*
If you lose your SmartKey, SmartKey with 
KEYLESS-GO, or mechanical key, you 
should do the following:
Have the SmartKey or SmartKey with 
KEYLESS-GO deactivated by an autho-
rized Mercedes-Benz Center.
Report the loss of the SmartKey, 
SmartKey with KEYLESS-GO, or the 
mechanical key immediately to your 
car insurance company.
Have the mechanical lock replaced if 
necessary.
Your authorized Mercedes-Benz Center 
will be glad to supply you with a 
replacement. 
!The trunk lid swings open upwards automat-
ically. Always make sure there is sufficient over-
head clearance.
Vehicles with trunk opening/closing system*: To 
stop the opening procedure, press button Š. 
The trunk lid stops moving.
iIf the trunk does not open, it is still locked 
separately (
page 117).
!If battery check lamp does not come on 
briefly during check, the SmartKey or SmartKey 
with KEYLESS-GO batteries are discharged.
Replace the batteries (
page 404). 
You can obtain the required batteries at any au-
thorized Mercedes-Benz Center.
iIf the batteries are checked within signal 
range of the vehicle, pressing the‹orŒ 
button will lock or unlock the vehicle according-
ly. 
404 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey or the 
SmartKey with KEYLESS-GO* are dis-
charged, the vehicle can no longer be 
locked or unlocked. It is recommended to 
have the batteries replaced at an 
authorized 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 / SmartKey with 
KEYLESS-GO*
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove the mechanical key from the 
SmartKey or SmartKey with 
KEYLESS-GO* (
page 399).
1Mechanical key
2Battery compartmentWarning!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 changing batteries, always replace 
both batteries.
The required replacement batteries are available 
at any Mercedes-Benz Center.