Page 251 of 341
248 Malfunction and warning messages
Te ch n ica l
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cluster displayPractical hints Car care Index
LIGHT SENSOR
With the electronic key removed and the driver’s door
open, a warning sounds and the message “SWITCH OFF
LIGHTS!” appears in the multifunction indicator if the
vehicle’s exterior lamps (except standing lamps) are not
switched off.REMOVE KEY
This message plus an audible alarm indicate that the
electronic key is in steering lock position 0 or 1, and the
driver’s door is open.
P54.30-3573-21
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253 Contents - Practical hints
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Practical hintsFirst aid kit .....................................254
Stowing things in the vehicle ......254
Fuses ................................................255
Hood .................................................257
Checking engine oil level .............260
Automatic transmission
fluid level ................................... 261
Coolant level ................................... 261
Adding coolant ...........................262
Windshield and headlamp
washer system ...........................263
Windshield and headlamp
washer fluid mixing ratio .........263Spare wheel, vehicle tools,
storage compartment ............... 264
Vehicle jack .................................... 265
Wheels ............................................ 266
Tire replacement ....................... 266
Rotating wheels ......................... 267
Spare wheel .................................... 268
Spare wheel bolts ...................... 268
Spare wheel .................................... 269
Changing wheels ............................271
Tire inflation pressure ..................276
Battery ............................................. 277
Jump starting ................................. 279
Towing the vehicle ........................ 282
Transmission selector lever,
manually unlocking ................. 284Exterior lamps ................................285
Headlamp assembly ...................286
Taillamp assemblies ..................289
Changing batteries in the
electronic main key .................. 291
Synchronizing
remote control ............................293
Emergency engine
shut-down ..................................293
Rear seat cushion ..........................294
Emergency operation of
sliding / pop-up roof .................295
Manual release for
fuel filler flap .............................296
Replacing wiper blade insert .......296
Trunk lamp .....................................298
Roof rack .........................................298
Page 281 of 341

278 Battery
Te ch n ica l
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must not leak acid when upside down for at least 15
minutes. Your authorized Mercedes-Benz Center can
provide such a special battery.
The service life of the battery is dependent on its
condition of charge. The battery should always be kept
sufficiently charged, in order to last an optimum length
of time.
Therefore, we strongly recommend that you have the
battery charge checked frequently, and corrected if
necessary, especially if you use the vehicle less than
approximately 200 miles (300 km) per month,
mostly for short distance trips, or if it is not used for
long periods of time.
Only charge a battery with a battery charger after the
battery has been disconnected from the vehicle’s
electrical circuit.
Always disconnect the battery negative lead first and
connect last.
When removing and connecting the battery, always
make sure that all electrical consumers are off and the
electronic key is in steering lock position 0. The battery,
its filler caps, the vent tube and the opposite plug must
always be securely installed when the vehicle in operation. During removal and installation always
protect the disconnected battery positive (+) terminal
with the cover attached to the battery.
While the engine is running the battery terminal clamps
must not be loosened or detached, otherwise the
generator and other electronic components would be
damaged.
Note:
After reconnecting the battery also resynchronize the
front seat head restraints, the express feature of the
power windows, and the electronic stability program
(ESP), see pages 48, 156 and 221.
Battery recycling
Batteries contain material that can harm the
environment with improper disposal.
Large 12 Volt storage batteries contain lead.
Recycling of batteries is the preferred method of
disposal.
Many states require sellers of batteries to accept old
batteries for recycling.
Page 285 of 341

282 Towing the vehicle
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Tow in g t h e ve hic l e
Important!
When towing the vehicle, please, note the following:
With the automatic central locking activated and the
electronic key in steering lock position 2, the vehicle
d oors l ock if th e l ef t front w heel as well as t he righ t rear
wheel are turning at vehicle speeds of approximately
9 mph (15 km / h) or more.
To prevent the vehicle door locks from locking,
deactivate the automatic central locking.
The rear towing eye is located at the right, below the
bumper.1Cover on right side of front bumper
To remove cover:
Press mark on cover in direction of arrow and lift cover
off to reveal threaded hole for towing eye bolt. The
towing eye bolt is supplied with the vehicle tools. Screw
towing eye bolt in to its stop and tighten with lug
wrench.
To reinstall cover:
Engage cover (1) at bottom and press in top securely.
Prior to towing the vehicle with all wheels on the
ground, make certain that the electronic key is in
steering lock position 2.If the electronic key is left in the steering lock
position 0 for an extended period of time, it can no
longer be turned in the lock. In this case, the
steering is locked. To unlock, remove electronic key
from steering lock and reinsert.
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283 Towing the vehicle
Te ch n ica l
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cluster displayPractical hintsCar care Index We recommend that the vehicle be transported using
flat bed equipment. This method is preferable to other
types of towing.
The vehicle may be towed with all wheels on the ground
and the selector lever in position “N” for distances up to
30 miles (50 km) and at a speed not to exceed 30 mph
(50 km / h). The electronic key must be in steering lock
position 2.
To be certain to avoid a possibility of damage to the
transmission, however, we recommend the drive shaft
be disconnected at the rear axle drive f lange for any
towing beyond a short tow to a nearby garage.
Do not tow with sling-type equipment. Towing with
sling-type equipment over bumpy roads will damage
radiator and supports.
Use wheel lift, dolly, or flat bed equipment, with
electronic key in steering lock turned to position 0.Note:
To signal turns while being towed with hazard warning
flasher in use, turn electronic key in steering lock to
position 2 and activate combination switch for left or
right turn signal in usual manner – only the selected
turn signal will operate.
Upon canceling the turn signal, the hazard warning
flasher will operate again.
Caution!
If the vehicle is towed with the front axle raised, the
engine must be shut off (electronic key in steering lock
position 0 or 1). Otherwise, the ESP will immediately be
engaged and will apply the rear wheel brakes. Switch off
t h e tow - aw ay a lar m a s we l l as t he ES P .
Wa r n i n g !
With the engine not running, there is no power
assistance for the braking and steering systems. In
this case, it is important to keep in mind that a
considerably higher degree of effort is necessary to
brake and steer the vehicle.
Page 294 of 341
291 Electronic main key
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index Changing batteries in the electronic main key
1Transmit buttons
2Lamp for battery check and function control
Checking batteries
If one of the transmit buttons (1) is pressed, the battery
check lamp (2) lights up briefly – indicating that the
batteries are in order.
Change batteries if the battery check lamp (2) does not
light up briefly.Changing batteries
Move locking tab (3) in direction of right arrow and
remove mechanical key (4, left arrow).
P80.20-2201-26
1
2
P80.35-2029-26
4
3
Page 295 of 341
292 Electronic main key
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Insert mechanical key (4) in side opening (5) to open
latch. Press briefly (do not use mechanical key as lever)
to release battery compartment.
Remove mechanical key from side opening.
Carefully remove battery compartment in direction of
arrow (6).Change batteries (7), inserting new ones under contact
spring (8) with plus (+) side facing up.
Return battery compartment into housing until locked
in place and slide mechanical key back into electronic
main key.
P80.35-2025-26
5
4
6
P80.35-2027-26
78
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293 Electronic main key
Te ch n ica l
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and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index Important!
Batteries contain materials that can harm the
environment if disposed of improperly. Recycling of
batteries is the preferred method of disposal. For
disposal, please follow manufacturer’s recommendation
on battery package.
Replacement Battery:
Lithium, type CR 2025 or equivalent.
Synchronizing remote control
The remote control may have to be resynchronized, if
the vehicle cannot be locked or unlocked.
To synchronize insert electronic key in starter switch.
The remote control should once again be operational.Emergency engine shut-down
If the engine can no longer be stopped using the
electronic key, the engine can be turned off by removing
two fuses.
For easy removal of fuses use the fuse extractor
(supplied with vehicle tool kit) to pull out the fuses
marked on the fuse chart as “ENGINE EMERGENCY
OFF”.
The fuse chart is also located in the vehicle tool kit,
seepage264.
For fuses see page 255.