Page 304 of 416

304 Practical hintsWhat to do if …?Display
Possible cause
Suggested solution
F 
CHIP CARD
DO NOT FORGET
This display appears (for a maximum of 
60 seconds) if the driver’s door is opened 
with the engine shut off and no SmartKey in 
the ignition.
Message is only a reminder.
Insert SmartKey in the ignition.
Take the KEYLESS-GO*card with you 
when leaving the vehicle.
B 
COOLANT
CHECK LEVEL!
The coolant level is too low.
Add coolant (
page 268).
If you have to add coolant frequently, 
have the cooling system checked by 
an authorized Mercedes-Benz Cen-
ter.
Warning!
G
Do not spill antifreeze on hot engine parts. 
Antifreeze contains ethylene glycol which 
may burn if it comes into contact with hot 
engine parts. You can be seriously burned.
!Do not ignore the low engine coolant 
level warning. Extended driving with 
the message and symbol displayed 
may cause serious engine damage not 
covered by the Mercedes-Benz Limited 
Warranty.
Do not drive without a sufficient 
amount of coolant in the cooling sys-
tem. The engine will overheat, causing 
major engine damage. 
         
        
        
     
        
        Page 307 of 416

307 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
G
DISPLAY MALFUNCTION
VISIT WORKSHOP!
The instrument cluster display is malfunc-
tioning.
Continue driving with added caution.
Visit an authorized Mercedes-Benz 
Center as soon as possible.
DISTRONIC
EXTERNAL INTERFERENCE
REACTIVATE!
Distronic* is switched off and is temporari-
ly unavailable.
Try activating Distronic* again later.
CLEAN SENSOR!
SEE OPERATOR'S MAN.
Distronic* is switched off because the Dis-
tronic* cover in the radiator grille is dirty.
Clean the Distronic* cover in the ra-
diator grille (
page 285).
Restart the vehicle.
VISIT WORKSHOP!
Distronic* is malfunctioning or the display 
is malfunctioning.
Visit an authorized Mercedes-Benz 
Center as soon as possible.
J 
DOOR OPEN!
You are attempting to drive with one or 
more doors open.
Close the doors.
P
SHIFT
TO P
You have turned off the engine with the 
KEYLESS-GO* start/stop button and 
opened the driver’s door.
Place the selector lever in positionP.
?
VISIT WORKSHOP!
There may be a malfunction in the:
Fuel injection system
Ignition system
Exhaust system
Fuel system
Visit an authorized Mercedes-Benz 
Center as soon as possible. 
         
        
        
     
        
        Page 326 of 416
326 Practical hintsUnlocking/locking in an emergency
Unlocking/locking in an emergencyUnlocking the vehicle
Unlocking the driver’s door
If you are unable to unlock the driver’s 
door with the SmartKey, open the door 
with the mechanical key as follows:
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in direction of ar-
row and slide the mechanical key2 out 
of the housing.
Unlock the door with the mechanical 
key. To do so, push the mechanical key 
into the lock until it stops and turn it 
counterclockwise to position1.
iUnlocking your vehicle with the me-
chanical key will trigger the anti-theft 
alarm system. To cancel the alarm, do 
one of the following:
Press button 
Œ 
or 
‹ 
on the 
SmartKey. 
Insert the SmartKey in the starter 
switch. 
If KEYLESS-GO* card present, 
press the KEYLESS-GO* start/stop 
button (
page 33). 
         
        
        
     
        
        Page 327 of 416

327 Practical hints
Unlocking/locking in an emergency
Unlocking the trunk
If you are unable to unlock the trunk with 
the SmartKey, open the trunk with the me-
chanical key as follows:Trunk lock
Insert the mechanical key into the 
trunk lid lock.
Turn the mechanical key counterclock-
wise to position1.
Press button2. 
The trunk lid swings open.
Locking the vehicle
If you are unable to lock the vehicle with 
the SmartKey or the KEYLESS-GO* card, 
lock it with the mechanical key as follows:
Close the passenger doors and the 
trunk lid.
Press the central locking switch in the 
center console (
page 103).
Check to see whether the locking knob 
on the passenger door is still visible. If 
necessary push it down manually.
Lock the driver’s door with the me-
chanical key.
Lock the trunk lid if necessary with the 
mechanical key (
page 326).
!The trunk lid swings open upwards au-
tomatically. Always make sure that 
there is sufficient overhead clearance. 
A minimum height clearance of 6 ft. 
(1.85 m) is required to open the trunk 
lid.iUnlocking your vehicle with the me-
chanical key will trigger the anti-theft 
alarm system. To cancel the alarm, do 
one of the following:
Press button 
Œ 
or 
‹ 
on the 
SmartKey. 
Insert the SmartKey in the starter 
switch. 
If KEYLESS-GO* card present, 
press the start/stop button 
(page 33). 
         
        
        
     
        
        Page 328 of 416

328 Practical hintsUnlocking/locking in an emergencyChanging batteries
If the batteries in the SmartKey or the 
KEYLESS-GO* card are discharged, the ve-
hicle can no longer be locked or unlocked. 
It is recommended to have the batteries re-
placed 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
1Mechanical key
2Battery compartment
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove mechanical key1.
Insert the mechanical key in side open-
ing and push gray slide.
The battery compartment is unlatched.
Pull the battery compartment out of the 
SmartKey housing in direction of ar-
row.
Remove the batteries.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help 
immediately.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are 
available at any authorized 
Mercedes-Benz Center. 
         
        
        
     
        
        Page 329 of 416
329 Practical hints
Unlocking/locking in an emergency
3Battery
4Contact spring
Using a lint-free cloth, insert new bat-
teries under the contact spring with the 
plus (+) side facing up. 
Return battery compartment into hous-
ing until it locks into place.KEYLESS-GO* card
1Battery cover
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Pry open cover 1 (e.g. by using a nar-
row blade screwdriver).
Remove the batteries.
Install new batteries as indicated by 
the “+” and “-” markings in the 
KEYLESS-GO card.
Replace battery cover 1.
Fuel filler flap
In an emergency, the fuel filler flap can be 
opened from the trunk. The release lever is 
located on the right-hand side in the trunk.
1Release knob
Open the trunk with the mechanical 
key (
page 326). 
Remove the trim inside the trunk on the 
right-hand side. 
Pull release lever1 in the direction of 
the arrow. 
The fuel filler flap can be opened. 
         
        
        
     
        
        Page 344 of 416

344 Practical hintsBattery
Battery
The battery is located on the right side of 
the trunk under the battery cover.
1Battery cover 
Pull on the outer, right-hand side of 
cover1 and remove it in the direction 
of the arrow.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Never lean over batteries while connecting, 
you might get injured.
Battery fluid contains sulfuric acid. Do not 
allow this fluid to come in contact with eyes, 
skin or clothing. In case it does, immediately 
flush affected area with water and seek 
medical help if necessary.
A battery will also produce hydrogen gas, 
which is flammable and explosive. Keep 
flames or sparks away from battery, avoid 
improper connection of jumper cables, 
smoking etc.Warning!
G
Do not place metal objects on the battery as 
this could result in a short circuit. 
Use leak-proof battery only to avoid the risk 
of acid burns in the event of an accident.
!Never loosen or detach battery termi-
nal clamps while the engine is running 
or the SmartKey is in the starter switch. 
Otherwise the alternator and other 
electronic components could be se-
verely damaged.
Have the battery checked regularly by 
an authorized Mercedes-Benz Center. 
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further 
information.Warning!
G
With a disconnected battery
you will no longer be able to turn the 
SmartKey in the starter switch and 
pressing the KEYLESS-GO* start/stop 
button (if so equipped) on the selector 
lever will have no effect
the selector lever will remain locked in 
positionP 
         
        
        
     
        
        Page 351 of 416

351 Practical hints
Towing the vehicle
Installing towing eye bolt
1Cover on right side of front bumper2Cover on right side of rear bumper
Removing cover
Press mark on cover in direction of ar-
row.
Lift cover off to reveal threaded hole for 
towing eye bolt.
Installing towing eye bolt
Take towing eye bolt and wheel wrench 
out of trunk (
page 322).
Screw towing eye bolt clockwise into 
its stop and tighten with wheel wrench.
!When towing the vehicle with all wheels 
on the ground, please note the follow-
ing:
With the automatic central locking acti-
vated and the SmartKey in starter 
switch position2, or KEYLESS-GO* 
start/stop button (if so equipped) in 
position2, the vehicle doors lock if the 
left front wheel as well as the right rear 
wheel are turning at vehicle speeds of 
approximately 9 mph (15 km/h) or 
more.
Switch off the tow-away alarm 
(page 84).
To prevent the vehicle doors from lock-
ing, deactivate the automatic central 
locking (
page 102).
Towing of the vehicle should only be 
done using the properly installed tow-
ing eye bolt. Never attach tow cable, 
tow rope or tow rod to vehicle chassis, 
frame or suspension parts.
iThe selector lever will remain locked in 
positionP and the SmartKey will not 
turn in the starter switch if the battery 
is disconnected or discharged. See 
notes on the battery (
page 344) or 
on jump starting (
page 347).