2008 MERCEDES-BENZ SLK55AMG key battery

398 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended
to have the batteries replaced at an autho-
rized 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.
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key from the
SmartKey (
page 394).1Mechanical key
2Battery compartment
Insert mechanical key1 into opening.
Press mechanical key1 in direction of
arrow.
Battery compartment2 is unlatched.
Pull battery compartment2 out of the
housing.
Warning!G
Batteries contain poisonous and corrosive
substances. Therefore keep the batteries
out of reach of children.
If a battery is swallowed, seek medical help
immediately.
Warning!G
SmartKey batteries contain Perchlorate
material, which may require special handling
and regard for the environment. Check with
your local government’s disposal guidelines.
California residents, see
http://www.dtsc.ca.gov/HazardousWaste
/Perchlorate/index.cfm.
iWhen inserting the batteries, make sure
they are clean and free of lint.
iWhen replacing batteries, always replace
both batteries.
The required replacement batteries are available
at any Mercedes-Benz Center.

399 Practical hints
Replacing SmartKey batteries
3Batteries
4Contact springs
Pull out batteries 3.
Using a lint-free cloth, insert new
batteries3 under contact springs4
with the positive terminal (+) side
facing up.
Return battery compartment2
(
page 398) into the housing until it
locks into place.
Slide the mechanical key back into the
SmartKey.
Check the operation of the SmartKey.

422 Practical hints
Battery
The battery is located in the engine com-
partment on the right-hand side below the
water tray (
page 423).
1Battery
2Positive terminal
3Negative terminal
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 302).
Never lean over batteries while connecting
them, as you could otherwise be injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come into contact with
eyes, skin or clothing. In case it does, imme-
diately 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 batteries only to avoid the
risk of acid burns in the event of an
accident.
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly by an
authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.

423 Practical hints
Battery
Disconnecting the battery
1Water tray
2Lock
Apply the parking brake (page 59).
Make sure the gear selector lever* is
set to positionP (manual transmission
to Neutral).
Turn off all electrical consumers.
Remove the SmartKey from the starter
switch.
Open the hood (page 294).
Turn locks2 one quarter turn.
Remove water tray1.
Read and observe safety instructions
and precautions (
page 302) and
(
page 422).
Use a 10 mm open-end wrench to dis-
connect the negative lead from battery
negative terminal3 (
page 422).
Remove the cover from battery positive
terminal 2 (
page 422).
Use a 10 mm open-end wrench to dis-
connect the positive lead from battery
positive terminal2 (
page 422).
Warning!G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch

automatic transmission*: the gear se-
lector lever will remain locked in
positionP
!Always disconnect the battery in the order
described below. Otherwise the vehicle’s
electronics can be damaged.

429 Practical hints
Towing the vehicle
Installing towing eye bolt
The towing eye bolt is supplied with the ve-
hicle tool kit, located in the compartment
underneath the trunk floor (
page 389).
The towing eyes are located on the passen-
ger side in the front and rear bumper.
Take vehicle tool kit out of trunk
(
page 389).
Front cover
1Cover in front bumper
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach a tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iWhen towing the vehicle with all wheels on
the ground, please note the following:
With the automatic central locking activated and
the SmartKey in starter switch 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.
To prevent the vehicle door locks from locking,
deactivate the automatic central locking
(
page 102).
iTo signal turns while being towed with the
hazard warning flasher in use, switch on ignition
and activate the combination switch for the left
or right turn signal in the usual manner – only the
selected turn signal will operate.
Upon canceling the turn signal, the hazard warn-
ing flasher will operate again.
iThe gear selector lever* will remain locked
in positionP (vehicles with automatic transmis-
sion*) and the SmartKey will not turn in the
starter switch if the battery is disconnected or
discharged. For more information, see “Battery”
(
page 422) or “Jump starting” (page 426).
Vehicles with automatic transmission*:
For information on manual unlocking of gear
selector lever, see (
page 396).

460 Index
Gear shifting malfunctions 167
Gearshift pattern 52
Kickdown 159
Kickdown, manual shift
program* 167
Manual shift program* 165
Program mode selector switch 161
Shifting procedure 156
Steering wheel gearshift control
one-touch gearshifting* 163
B
Backup lamp
Messages in the multifunction
display 383
Replacing bulbs 402
Bar 331
BAS 86
Batteries (SmartKey)
Replacing 398
Battery (Vehicle) 302, 422
Charging 424
Jump starting 426
Messages in the multifunction
display 372
Bead 331
Bi-Xenon headlamps* 401Brake Assist System see BAS
Brakes 280
Brake fluid 292, 454
Messages in the multifunction
display 373
SLK 55 AMG 281
Warning lamp 350
Break-in period 278
Bulbs
Messages in the multifunction
display 381–386
Replacing 400
C
California retail buyers and lessees,
Important notice for 11
Call priority, Tele Aid* 268
Capacities and recommended
fuels/lubricants 451
Carpets, cleaning 345
Catalytic converter 288
CD
Changer* 208, 253
Player/Changer*,
operation 134, 208
CD changer* (Audio system) 212Center console
Lamp 358
Lower part 30
Upper part 29
Central locking
Automatic 102, 146
Locking/unlocking from inside 103
SmartKey 62
Certification label 438
CHECK ENGINE indicator lamp 351
Checking tire pressure electronically
Tire Pressure Monitoring System
(TPMS), (USA only) 317
Children in the vehicle
Air bags 79
Infant and child restraint systems 79
Occupant Classification System
(OCS) 71
Passenger front air bag off indicator
lamp 74, 358
Chrome-plated exhaust tip*
Cleaning 346
Cigarette lighter 32, 256

465 Index
L
Labels 438
Lamp in center console 358
Lamps in instrument cluster 348
Lamps, indicator and warning
ABS 348, 349
Battery (SmartKey) 97
Brakes 350
CHECK ENGINE 351
ESP
®87, 352
Fuel reserve 355
Instrument cluster 356
Passenger front air bag off 74, 358
Seat belts 353–354
SRS 65, 355
Language in multifunction display (Control
system) 139
Layout of poly-V-belt drive 440
License plate lamps 402
Light alloy wheels
Cleaning 344
Technical data 442
Lighter see Cigarette lighterLighting 109
Combination switch 113
Corner-illuminating front fog
lamps* 114
Daytime running lamp mode 111
Door entry lamps 117
Exterior lamp switch 109
Exterior lamps, cleaning 343
Fog lamps 112
Footwell lighting* 117
Hazard warning flasher 115
Headlamp mode,
automatic/manual 110
High beam 113
High beam flasher 113
Individual settings (Control
system) 143
Instrument cluster illumination 118
Interior lighting 116
Low beam headlamps 109
Night security illumination (Control
system) 144
Reading lamps 117
Standing lamps 109
Trunk 116Limp-home mode 167
Loading 252, 307, 331
Locator lighting (Control system) 144
Locking
And parking 59
Centrally (Control system) 146
Centrally from inside 103
Locking knob (Doors) 98
Locking the vehicle 62
Long trip, checking before 292
Loss of
Service and Warranty Booklet 437
SmartKey or mechanical key 98
Low beam headlamps 109, 401
Lubricants, technical data 451
Luggage cover 32, 241
M
Main dimensions 449
Maintenance service indicator (Control
system) 337
Maintenance System 337
Manual seat see Seats
Manual shift program* 165
Deactivating 167

466 Index
Manual transmission 153
Driving 53
Gearshift pattern 51
Starting with SmartKey 51
Maximum inflation pressure 332
Maximum load rating 332
Maximum loaded vehicle weight 332
Mechanical key see SmartKey
Memory function* 107
Menus see Control system menus
Messages in the multifunction display see
Multifunction display messages
Mirror lamp* see Sun visors
Mirrors 168
Additional turn signals 401
Adjusting 46
Antiglare position 168
Auto-dimming* 168
Exterior rear view mirrors 46
Interior rear view mirror 46
Mobile phone see Telephone*
MOE tires* see MOExtended system*
MOExtended system* 321, 421
MON 292, 455Motor Octane Number see MON
MP3 210
Multifunction display 121
Multifunction display messages 360
ABS 362
Air bags 365–368
Battery, Vehicle 372
Brake fluid 373
Brakes 373
Bulbs 381–386
Coolant 374–376
Cruise control 362
Doors 371
Engine oil 377–379
ESP
®362, 363
Fuel 379
Hood 371
Low tire pressure 387
Maintenance service indicator 337
Parking brake 372
Passenger front air bag 367
Retractable hardtop 380, 388
Run Flat Indicator* 369
SmartKey 381SRS 364
Symbol messages 371
Telephone* 388
Text messages 362
Tire Pressure Monitoring System 370
Transmission 364
Trunk lid 371
Vehicle status message memory 135
Washer fluid 388
Multifunction steering wheel 28, 122
Heating* 276
N
Navigation system* 135
Neck-level heating see AIRSCARF*
Neutral gear position
Automatic transmission* 155, 157
Manual transmission 154
Night security illumination (Control
system) 144
Normal occupant weight 332
Number, Vehicle Identification (VIN) 438