Page 410 of 498
409 Practical hints
Replacing SmartKey batteries
Insert the mechanical key1 in direc-
tion of arrow in side opening.
Using mechanical key1 push gray 
slide2 to unlatch battery 
compartment3.
Pull the battery compartment3 out of 
the housing in direction of arrow.
4Battery
5Contact spring
Remove the batteries4 in direction of 
arrow.
Using a lint-free cloth, insert new 
batteries4 under the contact 
spring5 with the plus (+) side facing 
up. 
Return battery compartment3 into 
housing until it locks into place.
Slide mechanical key1 back into the 
SmartKey.
Check the operation of the SmartKey.
SmartKey with KEYLESS-GO*
Replacement batteries: Lithium, type 
CR 2025 or equivalent.
Remove mechanical key (
page 402).
Insert the mechanical key3 in side 
opening and push grey slide 
(page 408).
Battery compartment is unlatched.
Pull battery compartment out of the 
housing in direction of arrow 
(page 408).
 
     
        
        Page 411 of 498
410 Practical hintsReplacing SmartKey batteries1Battery
2Tilt battery up
3Mechanical key
Using mechanical key3 apply pres-
sure to position2.
Battery1 tilts up slightly.
Pull out batteries1 in direction of 
arrow.
Using a lint-free cloth, insert new 
batteries1 with the plus (+) side fac-
ing up.
Return battery compartment into hous-
ing until it locks into place.
Slide mechanical key1 back into the 
SmartKey.
Check the operation of the SmartKey 
and the KEYLESS-GO*.
 
     
        
        Page 432 of 498

431 Practical hints
Battery
Battery
Your vehicle is equipped with two batter-
ies:
Auxiliary battery (back-up battery; sta-
bilizes the electrical system if the main 
battery is discharged; located in engine 
compartment).
Main battery (starter and electrical 
consumers; located in the trunk under 
the luggage box).
Remove the luggage box (
page 401).
1Positive terminal cover
2Negative terminal
Warning!
G
Jump starting must only be done using the 
main battery in the trunk.Warning!
G
Failure to follow these instructions can 
result in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries 
(page 299).
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.!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 Maintenance Booklet for main-
tenance intervals or contact your 
authorized Mercedes-Benz Center for 
further information. 
     
        
        Page 435 of 498

434 Practical hintsBattery
Charge battery in accordance with the 
instructions of the battery charger 
manufacturer.
Reinstall the charged battery. Follow 
the previously described steps in re-
verse order.
Reconnecting the battery
Turn off all electrical consumers.
Remove the SmartKey from the starter 
switch.
Connect the positive lead and fasten its 
cover.
Connect the negative lead.
Install the luggage box (
page 401).
Batteries contain materials that can harm 
the environment if disposed of improperly. 
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.
!The battery, its filler caps and the 
battery ventilation tube must always be 
securely installed when the vehicle is in 
operation.
!Never invert the terminal connections!
iThe following procedures must be car-
ried out following any interruption of 
battery power (e.g. due to reconnec-
tion):
Set the clock (
page 162) 
(see COMAND operator’s manual).
Resynchronize the ESP
® 
(
page 368).
Resynchronize the side windows 
(page 216).
Resynchronize the tilt/sliding sun-
roof (
page 221). 
     
        
        Page 436 of 498

435 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can 
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:
Jump starting should only be performed 
when the engine and catalytic convert-
er are cold.
Do not start the engine if the battery is 
frozen. Let the battery thaw out first.
Only jump start from batteries with the 
same voltage rating (12 V). Jump start-
ing with a more powerful battery could 
damage the vehicle’s electrical system, 
which will not be covered by the 
Mercedes-Benz Limited Warranty.
Use only jumper cables with sufficient 
cross-section and insulated terminal 
clamps.
Warning!
G
Failure to follow these directions will cause 
damage to the electronic components, and 
can lead to a battery explosion and severe 
injury or death.
Never lean over batteries while connecting 
or jump starting, 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 very explosive. Keep 
flames or sparks away from battery, avoid 
improper connection of jumper cables, 
smoking, etc.
Attempting to jump start a frozen battery 
can result in it exploding, causing personal 
injury.
Read all instructions before proceeding.
!Do not tow-start the vehicle.!Jump starting must only be performed 
on the main battery installed in the 
trunk.
Avoid repeated and lengthy starting 
attempts.
Do not attempt to start the engine 
using a battery quick charge unit.
If the engine does not run after several 
unsuccessful starting attempts, have it 
checked at the nearest authorized 
Mercedes-Benz Center.
Excessive unburned fuel generated by 
repeated failed starting attempts may 
damage the catalytic converter and 
may present a fire risk.
Make sure the jumper cables do not 
have loose or missing insulation.
Make sure the cable clamps do not 
touch any other metal part while the 
other end is still attached to a battery. 
     
        
        Page 437 of 498

436 Practical hintsJump starting
Always make sure the jumper cables 
are not on or near pulleys, fans or other 
parts that move when the engine is 
started or running.
The main battery is located in the trunk un-
derneath the luggage box (
page 401).
Make sure the two vehicles do not 
touch.
Turn off all electrical consumers.
Apply parking brake.
Shift gear selector lever to positionP.
Connect positive terminals1 and3 
of the batteries with the jumper cable. 
Clamp cable to charged battery3 
first.
1Positive terminal of discharged battery
2Negative terminal of discharged bat-
tery
3Positive terminal of charged battery
4Negative terminal of charged battery
Start engine of the vehicle with the 
charged battery and run at idle speed.
Connect negative terminals4 and2 
of the batteries with the jumper cable. 
Clamp cable to charged battery4 
first.
Start the engine of the disabled vehi-
cle.
Now you can again turn on the electrical 
consumers. Do not turn on the lights under 
any circumstances.
Remove the jumper cables first from 
negative terminals2 and4 and then 
from positive terminals1 and3.
Now you can turn on the lights.
Have the battery checked at the near-
est authorized Mercedes-Benz Center.
Warning!
G
Keep flames or sparks away from battery. 
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries 
(page 299).
!Never invert the terminal connections!
iThe message 
Malfunction - electric 
consumers switched off
 may appear 
in the instrument cluster. It will disap-
pear as soon as the battery is suffi-
ciently charged. 
     
        
        Page 481 of 498

480 IndexAutomatic transmission 176
Accelerator position 180
Emergency operation 
(Limp-Home Mode) 190
Gear ranges 181
Gear selector lever position 178
Gear shifting malfunctions 190
Kickdown 180
Kickdown, manual shift program 
(CLS 55 AMG) 190
Manual shift program mode 
(CLS 55 AMG) 188
Manual shifting 183
One-touch gearshifting 183
Program mode selector switch 182
Selector lever position 176
Starting the engine 49
Winter program mode 182B
BabySmart
TM
Airbag deactivation system 78
Compatible child seats 471
Self-test 79
BabySmart
TM air bag deactivation 
system 471
Backrest
Seat, multicontour* 126
Seat, power 40
Backup lamps
Messages in display 387
Bar 332
BAS 86, 472
Batteries, SmartKey
Changing 408
Checking battery condition 102
Batteries, SmartKey with KEYLESS-GO*
Checking 109
Battery
Jump starting 435Battery, vehicle 431
Charging 433
Disconnecting 432
Messages in display 369, 373
Reconnecting 434
Removing 433
Bead 332
Bi-Xenon headlamps* 472
Block heater* (Canada only) 337
Brake assist system (BAS) 472
Brake fluid 291
Messages in display 377
Brake lamp
Messages in display 387
Brake pads
Message in display 374
Brakes
Warning lamp 354
Break-in period 278
Bulbs, replacing see Replacing bulbs 
     
        
        Page 487 of 498

486 IndexHood 293
Message in display 384
HVAC see 4-zone automatic climate 
control
Hydroplaning 283
I
Identification labels 446
Identification Number, Vehicle (VIN) 446
Ignition 36, 38, 50
Immobilizer 93
Indicator lamps see Lamps, indicator and 
warning
Infant and child restraint systems see 
Children in the vehicle
Information
About service and warranty 10
Button for Tele Aid 267
Inside door handle 111
Inside rear view mirror
Antiglare 191Installing
Infant and child restraint systems 80
Towing eye bolt 439
Wiper blades 418
Instrument cluster 24, 144, 474
Cleaning 349
Coolant temperature gauge 145
Illumination 144
Multifunction display 147
Outside temperature indicator 146
Interior lighting 141
Delayed switch-off 167
Interior rear view mirror 44
J
Jack 398, 399
Jacking up the vehicle 425
Jump starting 435K
Key, Mechanical 402
Key, SmartKey
Changing batteries 408
Key, SmartKey with KEYLESS-GO*
Changing batteries 409
KEYLESS-GO* 110, 474
Activating ignition with 38
Closing
Trunk 117
Factory setting 107
Global locking 107
Global unlocking 107
Important notes 105
Remote controls 103
Starting the engine 50
Turning off engine 60
Unlocking and opening, trunk 110
Unlocking with 35
Kickdown 180, 474
Kilopascal 333