2004 MERCEDES-BENZ S430 key battery

349 Practical hints
Unlocking/locking in an emergency
Unlocking the trunk
A minimum height clearance of 6 ft.
(1.85 m) is required to open the trunk lid.
If you are unable to unlock the trunk with
the SmartKey or KEYLESS-GO*, open the
trunk with the mechanical key.
The trunk lid lock is located above the rear
license plate recess.
1Unlocking and opening
Insert the mechanical key into the
trunk lid lock.

Turn the mechanical key counterclock-
wise to position1.
The trunk unlocks and opens.
Locking the vehicle
If you are unable to lock the vehicle with
the SmartKey or the SmartKey with
KEYLESS-GO*, 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 107).

Check to see whether the locking knob
on the passenger door is still visible. If
necessary push it down manually.

Slide mechanical key2 out of the
SmartKey (
page 348).

Lock the driver’s door with the me-
chanical key (
page 348).

Lock the trunk lid if necessary with the
mechanical key (if applicable)
(page 105).
Replacing 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 autho-
rized Mercedes-Benz Center.
!The trunk lid swings open upwards au-
tomatically. Always make sure that
there is sufficient overhead clearance.
Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.

350 Practical hintsUnlocking/locking in an emergencyBatteries 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
(page 348).

Insert the mechanical key1 in side
opening and push gray slide.
The battery compartment is unlatched.

Pull the battery compartment2 out of
the SmartKey housing in direction of
arrow.

Remove the batteries.3Battery
4Contact spring

Using a lint-free cloth, insert new
batteries3 under the contact
spring4 with the plus (+) side facing
up.

Return battery compartment into hous-
ing until it locks into place.
iWhen changing batteries, always re-
place both batteries.
The required replacement batteries are
available at any authorized
Mercedes-Benz Center.

351 Practical hints
Unlocking/locking in an emergency
SmartKey with KEYLESS-GO*
1Battery
2Tilt battery up
3Mechanical keyReplacement battery: Lithium, type
CR 2025 or equivalent.

Remove mechanical key (
page 348).

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.

Using mechanical key3, apply pres-
sure to position2.
Battery1 tilts up slightly.

Pull out battery1 in direction of ar-
row.

Using a lint-free cloth, insert new bat-
tery with the plus (+) side facing up.

Return battery compartment into hous-
ing until it locks into place.
Fuel filler flap
In case the central locking system does
not release the fuel filler flap, you can it
manually.
1Release knob
Open the trunk.

Remove the trim inside the trunk on the
right-hand side.

Pull release knob1 in the direction of
arrow.
The fuel filler flap can be opened.
iThe required replacement battery is
available at any authorized
Mercedes-Benz Center.

366 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 an 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 on the gear selector lever will
have no effect


the gear selector lever will remain
locked in positionP

372 Practical hintsTowing the vehicle
!
To be certain to avoid a possibility of
damage to the drive train, however, we
recommend the drive shaft be discon-
nected at the rear axle drive flange (ve-
hicles with 4MATIC: disconnected at
the front and rear axle drive flanges) for
any towing beyond a short tow to a
nearby garage.Warning!
G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:

the engine will not run


there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
as that will be necessary to adequately con-
trol the towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make certain that the SmartKey
is in starter switch position2.
If the SmartKey is left in starter switch
position0 for an extended period of time, it
can no longer be turned in the switch. In this
case, the steering is locked. To unlock, re-
move SmartKey from starter switch and re-
insert.Warning!
G
With the engine not running, there is no
power assistance for the brake 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 ve-
hicle. Adapt your driving accordingly.iThe gear 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 366)
or on jump starting (
page 369).
iTo signal turns while being towed with
the hazard warning flasher in use, turn
SmartKey in starter switch to
position2 and activate the combina-
tion switch for the left or right turn sig-
nal in the usual manner – only the
selected turn signal will operate.
Upon canceling the turn signal, the haz-
ard warning flasher will operate again.

405 Technical terms
Remote Vehicle Diagnostics
Transmission of vehicle data and cur-
rent location to the Mercedes-Benz
Customer Assistance Center for sub-
scribers to the Tele Aid service.
REST
(Residual engine heat utilization)
Feature that uses the engine heat
stored in the coolant to heat the vehi-
cle interior for a short time after the en-
gine has been turned off.
Restraint systems
Seat belts, belt tensioners, airbags and
child restraint systems. As indepen-
dent systems, their protective func-
tions complement one another.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 AN-
TI-KNOCK INDEX.
Shift lock
When the vehicle is parked, this lock
prevents the transmission selector le-
ver from being inadvertently moved out
of positionP without the SmartKey
turned and the brake pedal depressed.
SRS
(S
upplemental R
estraint S
ystem)
Seat belts, emergency tensioning de-
vice and airbags. Though independent
systems, they are closely interfaced to
provide effective occupant protection.Tele Aid System
(T
elematic A
larm I
dentification on
D
emand)
The Tele Aid system consists of three
types of response: automatic and man-
ual emergency, Roadside Assistance
and information. Tele Aid is initially ac-
tivated by completing a subscriber
agreement and placing an acquain-
tance call.
The Tele Aid system is operational pro-
vided that the vehicle’s battery is
charged, properly connected, not dam-
aged and cellular and GPS coverage is
available.
Telematics*
A combination of the terms “telecom-
munications” and “informatics.”
Tightening torque
Force times lever arm (e.g. a lug
wrench) with which threaded fasteners
such as wheel bolts are tightened.

409 Index
Automatic lighting control
Activating 129
Deactivating 130
Automatic locking when driving 106
Automatic transmission 164
Accelerator position 170
Comfortable program mode 170
Deactivating steering wheel gearshift
control 173
Emergency operation
(Limp Home Mode) 173
Fluid level 278
Gear ranges 166
Gear selector lever position 167
Gear shifting malfunctions 173
Kickdown 170
One-touch gearshifting 165
Program mode selector switch 170
Selector lever position 164
Starting the engine 43
Steering wheel gearshift control
(Speedshift) S 55 AMG 168
Transmission fluid 278
Winter program mode 171
Auxiliary fuse box 374B
BabySmart
TM
Airbag deactivation system 71
Compatible child seats 71, 401
Self-test 71
BabySmart
TM airbag deactivation
system 401
Backrest supports
Lumbar region 113
Shoulder region 112
Backup lamps 354, 358
Bulbs 354
BAS 78, 401
Messages in display 315
Batteries, SmartKey
Changing 350
Check lamp 90, 91
Replacing 349
Battery discharged
Jump starting 369
Battery, SmartKey with KEYLESS-GO*
Changing 351
Check lamp 95Battery, vehicle 280, 366
Charging 367
Disconnecting 367
Reconnecting 368
Reinstalling 367
Removing 367
Bi-Xenon headlamps 401
Block heater (Canada only) 293
Blocking
Rear window operation 74
Brake assist system (BAS) 401
Brake fluid 270, 394
Brake lamp bulbs 354
Brake lamp, high mounted 354
Brake pads
Message in display 321
Brakes 260
Warning lamp 305
Break-in period 258
Bulbs, replacing 353
Additional turn signals 353
Backup lamps 354
Brake lamps 354

410 Index
Fog lamps 353
Front lamps 353
High beam 353
High mounted brake lamp 354
License plate lamps 354, 358
Low beam 353
Parking and standing lamps 353
Parking lamps 354, 357
Rear fog lamp 354
Rear fog lamps 358
Side marker lamps 353, 357
Standing lamps 353, 354, 357
Tail lamp assemblies 354, 358
Turn signal lamps 353, 354
C
CAC (Customer Assistance Center) 402
Calling up
Distronic* settings 147
Range (distance to empty) 150
Service indicator 295
CAN system 402
Cargo tie-down hooks 230Cassette player
Operating 141
Catalytic converter 267
CD changer* 142
CD mode 142
CD player
Operating 141
Center console 25
AIRBAG OFF indicator lamp 311
Centigrade
Setting temperature units 154
Central locking
Automatic 106
From inside 107
Switch 107
Switching on/off (control
system) 159
Unlocking from inside 107
Changing
Batteries (SmartKey) 350
Battery (SmartKey with
KEYLESS-GO*) 351
CDs 142SmartKey setting 160
Vehicle level 219, 222
Charcoal filter 188
Activating 188
Deactivating 189
Charging
Vehicle battery 367
CHECK ENGINE malfunction indicator
lamp 306
Checking
Brake fluid 270
Coolant level 278
Oil level 271, 273
Oil level via control system 274
Tire inflate pressure 271
Vehicle lighting 271
Child safety 69
Airbags 60
Infant and child restraint systems 64,
69
LATCH child seat anchors 73
Cigarette lighter 239