Page 413 of 506

412 Practical hintsReplacing batteries in the SmartKey/ SmartKey with KEYLESS-GO*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
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key1
(page 397).
1Mechanical key
2Battery compartment
Insert mechanical key 1 in side
opening and push gray slide.
Battery compartment2 is unlatched.
Pull battery compartment 2 out of the
SmartKey housing in direction of
arrow.
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 changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.
Page 466 of 506

465 Technical terms
Restraint systems
Seat belts, child restraints, lower an-
chors and tethers for children (LATCH).
As independent systems, their protec-
tive functions complement one anoth-
er.
Rim
(
page 337)
Roll bars
Occupant protection system which
consists of tubular steel, integrated in
the rear head restraints. The roll bars
are lowered into the car body during
normal driving conditions and raised
automatically in an accident or in a crit-
ical driving situation.RON
(R
esearch O
ctane N
umber)
The Research Octane Number for gaso-
line as determined by a standardized
method. It is an indication of a gaso-
line's ability to resist undesired detona-
tion (knocking). The average of both
the ->MON (Motor Octane Number)
and RON (Research Octane Number) is
posted at the pump, also known as
ANTI-KNOCK INDEX.
Shift lock
When the vehicle is parked, this lock
prevents the gear selector lever from
being inadvertently moved out of
positionP without SmartKey turned
and brake pedal depressed.
Sidewall
(
page 337)Soft top
Soft top roof that can be opened by
pulling and closed by pressing a switch
and stored in the soft top compartment
in the trunk area.
Speedshift (CLK 500, CLK 55 AMG)
Steering wheel gearshift control. You
can change the gears yourself with the
steering wheel gearshift buttons.
SRS
(S
upplemental R
estraint S
ystem)
Air bags, air bag control unit (with
crash sensor), emergency tensioning
device. Though independent systems,
they are closely interfaced to provide
effective occupant protection.
Page 469 of 506

468 IndexAir bags 61
Children 62
Front 65
Head-thorax 66
Passenger 65
Rear side-impact 67
Safety guidelines 64
Air conditioning (cooling) 187
Turning off 188, 198
Turning on 188, 198
Air conditioning refrigerant 456
Air distribution
Adjusting 184, 194
Air pressure 335
Air pressure see Tire inflation pressure
Air recirculation mode 186, 195
Activating 186, 196
Deactivating 187, 196
Air vents, rear passenger compartment
Adjustable 189, 200
Air volume
Adjusting 184, 194
Alarm
Audible 83, 91, 92
Canceling 91, 92
Visual 89Alarm system
Anti-theft 89
Alignment bolt 424
Alignment bolt (vehicle tool kit) 461
Anticorrosion/antifreeze 459
Antiglare
Auto-dimming 176
Antilock brake system (ABS) 461
Anti-theft alarm system
Arming 90
Canceling alarm 91, 92
Disarming 90
Anti-theft systems 89
Anti-theft alarm system 89
Immobilizer 89
Tow-away alarm 91
Aquaplaning see Hydroplaning
Armrest
Storage box 271
Storage compartments 270
Ashtray (Center console) 273
Opening 273
Reinstalling 273
Removing 273
Ashtray (Rear seat) 273
Opening 274Aspect ratio 335
At the gas station 302
ATF (automatic transmission fluid) 309
AUDIO menu 139
Selecting radio station 139
Selecting satellite radio* station 140
Audio system 201
Audio and telephone, operation 201
Button and soft key operation 204
CD operation 218
Operating and display elements 202
Operating safety 201
Operation 204
Radio operation 209
Sound system 201
Switching off 204
Switching on 204
Telephone* operation 224
Auto-dimming for rear view mirror 176
Automatic central locking
Activating/deactivating
(control system) 155
Locking/unlocking
(central locking switch) 110
Page 472 of 506

471 Index
Central locking
Automatic 110
From inside 110
Locking from inside 110
Switch 110
Switching on/off
(control system) 155
Unlocking from inside 110
Central locking switch 110
Certification label 442
Changing
CDs 218
Key setting 156
Charcoal filter 197
Activating 197
Deactivating 197
Charging
Vehicle battery 428
CHECK ENGINE
malfunction indicator lamp 356
Checking
Coolant level 310
Oil level 304, 307
Tire inflate pressure 304
Vehicle lighting 304Child safety 72
Air bags 62
Front passenger front
air bag off indicator lamp 79
Infant and child
restraint systems 67, 72
LATCH child seat anchors 80
OCS 75
Child safety switch see
Blocking of rear window operation
Child seat anchors see
LATCH child seat anchors
Cigarette lighter 274Cleaning 345
Cup holder 351
Gear selector lever 351
Hard plastic trim items 351
Headlamps 176
Headliner 351
Instrument cluster 351
Leather upholstery 352
Light alloy wheels 350
Nubuck leather upholstery
(CLK 55 AMG) 352
Parktronic system* sensor 349
Plastic and rubber parts 352
Seat belts 351
Soft top 347
Steering wheel 351
Upholstery 352
Windows 350
Windshield 53
Wiper blades 349
Wood trims 352
Cleaning and care of vehicle 345
Cleaning tires 315
Climate control 180
Clock 25, 148
Page 488 of 506

487 Index
Resetting
All functions (control system) 142
All functions of a submenu 143
Fuel consumption 159
Maintenance service indicator 344
Trip odometer 131
Residual heat utilization 199, 464
Residual ventilation 199
REST
(Residual engine heat utilization) 464
Restraint system see
Infant and child restraint systems
Restraint systems 465
Rim 337
Rims 445
Roadside Assistance 12
Tele Aid 280
Roll bar 71, 465
Lowering manually 402
Messages in display 387
Operating manually 401
Warning lamp 359
RON 303
RON (Research Octane Number) 465
Rubber parts
Cleaning 352S
Safety
Occupant 60
Safety belts see Seat belts
Safety defects
Reporting 18
Safety systems
Driving 84
Satellite radio
additional text information 217
general information 213
manual channel input 215
storing of station 217
Seat belt force limiter 70
Seat belts 67
Cleaning 351
Fastening 43
Proper use of 45, 69
Safety guidelines 64
Warning lamp 359
Seat cushion depth
Adjusting 116
Seat heating* 117
Switching on/off 117
Seat ventilation* 118
Switching on/off 118Seating capacity 318
Seats 112
Adjusting 37
Easy entry/exit feature 112
Multicontour seat* 116
Seat heating* 117
Seat ventilation* 118
Selecting
Display 146
station (satellite radio) 215
Selecting display 147
Selecting radio mode 209
Selector lever
Lock 47
Message in display 373
Self-test
OCS 80
Tele Aid 277
Service
Parts service 440
Service (maintenance) 342