2008 MERCEDES-BENZ C300 keyless

448 Practical hints
Battery
Starter battery
1Battery
2Positive terminal
3Negative terminal
4Ventilation hose
Disconnecting the battery
Apply the parking brake (page 134).
Make sure gear selector lever* is set to
positionP (manual transmission to
Neutral).
Turn off all electrical consumers.
Remove SmartKey from starter switch.Vehicles with KEYLESS-GO* (Canada
only):
Press the start / stop button until
the engine shuts off.
Open the driver’s door.
Open the hood (page 325).
Remove the filter box (page 447).
Read and observe safety instructions
and precautions (
page 446).
Disconnect the battery negative lead
from negative terminal3.
Remove cover from the positive
terminal2.
Disconnect the battery positive lead.iIf the battery is discharged, you must use
the mechanical key to unlock (
page 424) or
lock (
page 425) the vehicle.
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 (Canada only) will have no effect

vehicles with automatic transmission*:
the gear selector lever will remain
locked in positionP
!Always disconnect the starter battery in the
order described below. You could otherwise
damage the vehicle’s electronics.

450 Practical hints
Battery
Reconnecting the battery
Turn off all electrical consumers.
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO* (Canada
only):
Open the driver’s door.
Connect the battery positive lead and
fasten its cover (
page 448).
Connect the battery negative lead
(
page 448).
Make sure that the ventilation hose4
is attached to the battery.
Reinstall filter box (page 447).
!Always connect the starter battery in the or-
der described below. Otherwise, the vehicle’s
electronics could be damaged.
!Never invert the terminal connections.
!Make sure the battery has a plug where the
ventilation hose
4 is attached to it.
iThe following procedures must be carried
out following any interruption of battery power
(e.g. due to reconnecting):

Reset the automatic exterior mirror fold in
function (
page 99).

Set the clock (page 170).
Vehicles with COMAND*: see COMAND op-
erator’s manual.

453 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.When circumstances do not permit the
recommended towing methods, the
vehicle may be towed with all wheels on
the ground or front wheels raised (except
vehicles with 4MATIC) only so far as neces-
sary to have the vehicle moved to a safe
location where the recommended towing
methods can be employed.
When towing the vehicle with all wheels on
the ground or the front axle raised (not per-
missible for vehicles with 4MATIC), the ve-
hicle may be towed only for distances up to
30 miles (50 km) and at a speed not to ex-
ceed 30 mph (50 km/h).
!Vehicles with automatic transmission*
and/or 4MATIC:
Do not tow-start the vehicle.
!Use flatbed or wheel lift/dolly equipment
with SmartKey or SmartKey with KEYLESS-GO*
(Canada only) in starter switch turned to
position0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Switch off the ESP
® (page 63) and the auto-
matic central locking (
page 173).
!Vehicles with 4MATIC:
Do not tow with one axle raised. Doing so could
damage the transfer case, which is not covered
by the Mercedes-Benz Limited Warranty.
All wheels must be on or off the ground. Observe
instructions for towing the vehicle with all
wheels on the ground.
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 brake
system

there is a malfunction in the power
supply or in the vehicle’s electrical
system
This is necessary to adequately control the
towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the SmartKey or
SmartKey with KEYLESS-GO* (Canada only)
is in starter switch position2.

454 Practical hints
Towing the vehicle
Warning!G
Without the engine running, there is no pow-
er assistance for the brake and steering sys-
tems. 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. Adapt your driving accordingly.
iWhen towing the vehicle with all wheels on
the ground, please note the following:
With the automatic central locking activated and
the SmartKey or SmartKey with KEYLESS-GO*
(Canada only) in starter switch position 2, the ve-
hicle 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 doors from locking,
deactivate the automatic central locking
(
page 173).
!If the vehicle is towed with the front axle
raised (not permissible for vehicles with
4MATIC), the gear selector lever must be in
positionN (manual transmission: gear shift lever
in neutral position) and the engine must be shut
off (SmartKey or SmartKey with KEYLESS-GO*
(Canada only) in starter switch position0 or1).
Active braking action through the ESP
® may
otherwise seriously damage the brake system.
While towing, the battery must be connected and
charged. Otherwise:

you will not be able to switch on the ignition

you will not be able to engage the automatic
transmission* in positionN (
page 127)
When towing the vehicle with all wheels on the
ground, the gear selector lever must be in
positionN (manual transmission: gear shift lever
in neutral position) and the SmartKey or
SmartKey with KEYLESS-GO* (Canada only)
must be in starter switch position2.
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach tow cable, tow rope or tow rod to
vehicle chassis, frame or suspension parts.
iTo signal turns while being towed with the
hazard warning flasher in use, turn SmartKey or
SmartKey with KEYLESS-GO* (Canada only) in
starter switch to position2 and activate the
combination 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 hazard
warning flasher will operate again.
!Make sure the parking brake is released.
iIf the battery is disconnected or discharged

the SmartKey or SmartKey with KEY-
LESS-GO* (Canada only) will not turn in the
starter switch

Vehicles with automatic transmission*: the
gear selector lever will remain locked in
positionP (
page 127).
For more information see “Battery”
(
page 446) and see “Jump starting”
(
page 451).

456 Practical hints
Fuses
The electrical fuses in your vehicle serve to
switch off malfunctioning power circuits.
If a fuse is blown, the component(s) and
systems secured by that fuse will stop op-
erating.If a newly inserted fuse blows again, have
the cause determined and rectified at an
authorized Mercedes-Benz Center.
A fuse chart explains the fuse allocation
and fuse amperages. It is located in the
main fuse box in the passenger compart-
ment (
page 457).
The electrical fuses are located in different
fuse boxes:

Fuse box in passenger compartment
(
page 457)

Fuse box in engine compartment
(
page 457)

Fuse box in trunk (page 458)Before replacing fuses:
Depress the parking brake
(
page 134).
Make sure the manual transmission is
in Neutral (
page 136), automatic
transmission* is set to P (
page 140).
The gear position indicator in the ta-
chometer display should be on P.
Turn off all electrical consumers.
Turn off the engine (page 134).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*
(Canada only):
Open the driver’s door.
Warning!G
Only use fuses approved by Mercedes-Benz
with the specified amperage for the system
in question and do not attempt to repair or
bridge a blown fuse. Using other than ap-
proved fuses or using repaired or bridged
fuses may cause an overload leading to a
fire, and/or cause damage to electrical
components and/or systems. Have the
cause determined and remedied at an au-
thorized Mercedes-Benz Center.
iA blown fuse must be replaced by an appro-
priate spare fuse (recognizable by its color or the
fuse rating given on the fuse) of the amperage
recommended in the fuse chart.
Any Mercedes-Benz Center will be glad to advise
you on this subject.
!Switch off the vehicle’s internal electrical
functions (
page 448) when you are working on
the fuses.
iIn case of a blown fuse contact Roadside
Assistance or an authorized Mercedes-Benz
Center.

488 Index
Phone cook 233
Radio operation 194
Satellite radio* operation 200
Sound settings 189
Surround sound* (Canada only) 190
SYS menu 192
SYS menu, Bluetooth
® settings 192
SYS menu, display settings 192
SYS menu, language settings 193
SYS menu, reset to factory
settings 193
Telephone menu* 222
Volume 189
Auto-dimming*, Rear view mirrors 100
Automatic central locking 80
Activating/deactivating
(Control system) 173
Automatic climate control (3-zone) see Cli-
mate control system
Automatic headlamp mode 109, 172
Automatic lighting control, Interior
lighting 115
Automatic shift program 144Automatic transmission
Accelerator position 142
Emergency operation (limp-home
mode) 146
Fluid 476, 477
Fluid level 328
Gear ranges 143
Gear shifting malfunctions 146
Hill start assist system 246
Kickdown 142
Shifting procedure 139
Starting the engine 127
Transmission fluid 328
Automatic transmission*
Automatic shift program 144
Gear selector lever 138
Gear selector lever control one-touch
gearshifting 145
Gear selector lever positions 140
Program mode selector switch 144
Aux socket 220B
Backrest 281
Backup lamps
Replacing bulbs 430, 431
Bar 356
BAS 60
Batteries, SmartKey
Checking battery condition 78
Replacing 428
Batteries, SmartKey with KEYLESS-GO*
(Canada only)
Checking battery condition 78
Replacing 428
Battery 448
Battery, vehicle 446
Charging 449
Discharged, Jump starting 451
Disconnecting 448
Message in display 399
Reconnecting 450
Removing 449
Bead 356
Beverage holder see Cup holder

495 Index
H
Halogen headlamp see Headlamps
Hands-free microphone 31
Hard plastic trim items, cleaning 370
Hazard warning flasher 114
Head restraints 89
Active head restraints 50
Adjustment 89
Front seat 89
Rear seat, Removing and
installing 90
Resetting activated active head
restraints 427
Headlamp cleaning system 112, 330
Washer fluid 479, 486
Headlamps
Automatic control 109
Automatic headlamp mode 172
Cleaning lenses 367
Cleaning system 330
Halogen 432
Manual headlamp mode 172
Messages in display 411
Refilling washer fluid 330
Replacing bulbs 431, 432Headliner and shelf below rear window,
Cleaning and care of 371
High beam flasher 112
Replacing bulbs (Bi-Xenon*) 431,
435
Replacing bulbs (Halogen) 431, 433
High beam headlamps
Indicator lamp 27
Replacing bulbs (Bi-Xenon*) 431
Replacing bulbs (Halogen) 431, 433
Replacing bulbs for high beam flasher
(Bi-Xenon*) 435
High mounted brake lamp 431
Hood 325
Message in display 406
Opening 325
Horn 25
Hot weather performance 483
HVAC see Climate control system
Hydroplaning 315I
Identification labels 462
Identification Number, Vehicle (VIN) 463
Ignition 82, 84, 127
Switching on 82
Switching on, KEYLESS-GO* 84
Immobilizer 66
Infant and child restraint systems see Chil-
dren in the vehicle
Inside door handle 79
Instrument cluster 26, 147
Coolant temperature gauge 27, 148
Fuel gauge 27, 150
Illumination 148
Lamps 374
Multifunction display 151
Outside temperature indicator 149
Setting the language (Audio
system) 193
Interior lighting 114
Activating automatic control 115
Deactivating automatic control 115
Delayed shut-off 173
In the rear 116
Reading lamps in the front 115, 116
Reading lamps in the rear 116

496 Index
Interior rear view mirror
Adjusting 97
Auto-dimming 99, 100
Interior storage spaces see
Storage compartments
J
Jack 421
Jump starting 451K
Key, Mechanical 424
Loss of 79
Key, SmartKey 70
Battery check lamp 70, 72
Factory setting 71
Global locking and unlocking 71
Lock button 70
Locking and unlocking 70
Loss of 79
Messages in display 408
Opening button for trunk 70
Panic button 58
Remote control 70
Restoring to factory setting 73
Selective setting 72
Starting the engine 127
Steering wheel lock 82
Switching on ignition with 82
Turning off engine 135
Unlock button 70Key, SmartKey with KEYLESS-GO* 73
Battery check lamp 73, 77
Closing, Trunk 269
Factory setting 76
Global locking and unlocking 77
Important notes on using
KEYLESS-GO* 75
Locking and unlocking 73
Opening button for trunk 73
Panic button 58
Restoring to factory setting 78
Selective setting 77
Starting the engine 128
Switching on ignition with 84
Unlock button 73
Key, SmartKey with KEYLESS-GO*
(Canada only)
Lock button 73
Loss of 79
Messages in display 407
Remote control 73
Turning off engine 135
Kickdown 142
Kilopascal 357