2008 MERCEDES-BENZ GL550 engine

57 Getting started
Driving
Starting with the SmartKey
For information on turning off the engine
with the SmartKey, see “Turning off the en-
gine” (
page 68).
Gasoline engine
Make sure the automatic transmission
is set toP.
The transmission position indicator in
the multifunction display should be
on
P (page 155).
Do not depress the accelerator.
Turn the SmartKey in the starter switch
to position3 (
page 41) and hold until
the engine starts.Diesel engine
Make sure the automatic transmission
is set toP.
The transmission position indicator in
the multifunction display should be
on
P (page 155).
Do not depress the accelerator.
Turn the SmartKey in the starter switch
to position2 (
page 42).
Preglow indicator lampqin the
instrument cluster comes on.
As soon as preglow indicator
lampq goes out, turn the SmartKey
in the starter switch to position3
(
page 42) and release it.
The engine starts automatically.Starting with KEYLESS-GO*
You can start your vehicle without the
SmartKey in the starter switch using the
KEYLESS-GO start/stop button in the
starter switch.
The SmartKey with KEYLESS-GO must be
located in the vehicle.
iYou can also use the “touch-start” function.
Turn the SmartKey to position3 and release it
again immediately. The engine then starts auto-
matically.
iIf the engine is at operating temperature,
preglow indicator lampqmay not stay on
and you can start the engine without preglowing.
Warning!G
As long as the SmartKey with KEYLESS-GO
is in your vehicle, the vehicle can be started.
Therefore, never leave children unattended
in the vehicle, as they could otherwise acci-
dentally start the engine.
When leaving the vehicle, always take the
SmartKey with KEYLESS-GO with you and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle.
164.boo Seite 57 Freitag, 30. März 2007 12:54 12

58 Getting started
Driving
KEYLESS-GO start/stop button
1USA only
2Canada only
Make sure KEYLESS-GO start/stop
button1 is inserted in the starter
switch (
page 43).
For information on turning off the engine
with KEYLESS-GO, see “Turning off with
KEYLESS-GO*” (
page 69).Gasoline engine
Make sure the automatic transmission
is set toP.
The transmission position indicator in
the multifunction display should be
on
P (page 155).
Depress the brake pedal during the
starting procedure.
Do not depress the accelerator.
Press KEYLESS-GO start/stop
button1 once.
The engine starts if the SmartKey with
KEYLESS-GO is in the vehicle.Diesel engine
Make sure the automatic transmission
is set toP.
The transmission position indicator in
the multifunction display should be
on
P.
Depress the brake pedal during the
starting procedure.
Do not depress the accelerator.
Press KEYLESS-GO start / stop
button1 once.
The engine preglows and starts if the
SmartKey with KEYLESS-GO is in the
vehicle.
iIf you wish to start the engine using the
SmartKey instead of the KEYLESS-GO feature,
remove the KEYLESS-GO start/stop button from
the starter switch (
page 43).
iIf the engine is at operating temperature,
the time the engine needs to preglow is reduced.
164.boo Seite 58 Freitag, 30. März 2007 12:54 12

59 Getting started
Driving
Starting difficulties
If the engine does not start as described,
carry out the following steps:
If you are starting the engine with the
SmartKey, turn SmartKey in starter
switch to position0 and repeat starting
procedure.
If you are starting the engine with
KEYLESS-GO*: Close any doors that
may be open to allow for better
detection of the SmartKey with
KEYLESS-GO*.
Or:
Remove KEYLESS-GO* start/stop
button from starter switch (
page 43).
Start the engine with the SmartKey as
radio signals from another source may
be interfering with the SmartKey with
KEYLESS-GO*.
Repeat the starting procedure
(
page 56). Remember that extended
starting attempts can drain the battery.
Get a jump start (page 536).
If the engine does not start after several
starting attempts, there could be a mal-
function in the engine electronics or in the
fuel supply system.
Contact an authorized Mercedes-Benz
Light Truck Center or call Roadside
Assistance.
Parking brake
1Release handle
Release the parking brake by pulling on
release handle1.
The warning lamp; (USA only)
or3(Canada only) in the
instrument cluster goes out.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Children could release the
parking brake, which could result in an acci-
dent and/or serious personal injury.
164.boo Seite 59 Freitag, 30. März 2007 12:54 12

60 Getting started
Driving
Driving off
Depress the brake pedal.
The gear selector lever can now be
used.
Shift automatic transmission toD orR
(
page 191).
Release the brake pedal.
Carefully depress the accelerator
pedal.After a cold start, the automatic transmis-
sion shifts at a higher engine revolution.
This allows the catalytic converter (gaso-
line engine) or the oxidation catalyst (die-
sel engine) to reach its operating
temperature earlier.
iWait for the gear selection process to com-
plete before setting the vehicle in motion.
iShifting from gear positionP to positionR,
N, orD is only possible with the brake pedal
depressed. Without the brake pedal depressed,
the gear selector lever can be moved, but the
parking pawl remains engaged, not allowing
shifting to occur.
!If you hear a warning signal and the
message
Release Parking Brake appears in
the multifunction display when driving off, you
have forgotten to release the parking brake.
Release the parking brake (
page 59).
iOnce the vehicle is in motion, the automatic
central locking system engages and the locking
knobs drop down.
The automatic door lock feature can be
deactivated (
page 180).
You can open a locked door from the inside.
Open door only when conditions are safe to do
so.
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of loss of control.
Warning!G
It is dangerous to shift the automatic trans-
mission out ofP orN if the engine speed is
higher than idle speed. If your foot is not
firmly on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
164.boo Seite 60 Freitag, 30. März 2007 12:54 12

61 Getting started
Driving
For more information, see “Driving instruc-
tions” (
page 347).
For information on off-road driving, see
“Off-road driving” (
page 355).
Switching on headlamps
Low beam headlamps
The exterior lamp switch is located on the
dashboard to the left of the steering wheel.
Exterior lamp switch
1Off
2Low beam headlamps on
Switch on the ignition (page 41).
Turn the exterior lamp switch to
positionB.
The low beam headlamps come on.High beam
The combination switch is located on the
left of the steering column.
Combination switch
1High beam
2High beam flasher
Push the combination switch in
direction of arrow1.
The high beam headlamp indicator
lampA in the instrument cluster
comes on (
page 26).
For more information on headlamps, see
“Lighting” (
page 143).
!Shift the automatic transmission to
positionPorR only when the vehicle is stopped
in order to avoid damaging the transmission.
!Do not run cold engine at high engine
speeds. Running a cold engine at high engine
speeds may shorten the service life of the
engine.
!Simultaneously depressing the accelerator
pedal and applying the brakes reduces engine
performance and causes premature brake and
drivetrain wear.
164.boo Seite 61 Freitag, 30. März 2007 12:54 12

62 Getting started
Driving
Turn signals
The combination switch is located on the
left of the steering column.
Combination switch
1Turn signals, right
2Turn signals, left
Press the combination switch in
direction of arrow1 or2.
The corresponding turn signal indicator
lampL orK in the instrument
cluster flashes (
page 26).The combination switch resets automati-
cally after major steering wheel move-
ment.
Windshield wipers
The combination switch is located on the
left of the steering column.
Combination switch
1Single wipe
Wiping with windshield washer fluid
2Switching on windshield wipers
Switch on the ignition (page 42).
iTo signal minor directional changes such as
changing lanes, press combination switch only
to point of resistance and release. The corre-
sponding turn signal will flash three times.
!Do not operate the windshield wipers when
the windshield is dry. Dust that accumulates on
a windshield might scratch the glass and/or
damage the wiper blades when wiping occurs on
a dry windshield. If it is necessary to operate the
windshield wipers in dry weather conditions,
always operate the windshield wipers with wind-
shield washer fluid (
page 64).
!If anything blocks the windshield wipers
(leaves, snow, etc.), switch them off immediate-
ly.

For safety reasons, stop the vehicle in a safe
location and

remove SmartKey from starter switch
or

turn off the engine by pressing the
KEYLESS-GO* start/stop button and
open the driver’s door (with the driver’s
door open, starter switch is in
position0, same as with SmartKey
removed from starter switch)
before attempting to remove any blockage.

Remove blockage.

Turn the windshield wipers on again.
164.boo Seite 62 Freitag, 30. März 2007 12:54 12

65 Getting started
Driving
Deactivating intermittent wipe
Turn rear window wiper switch1 to
position4 (
page 64).
Indicator6 (
page 64) for the rear
window wiper is cleared from the lower
multifunction display, indicating that
the rear window wiper is deactivated.
Wiping with windshield washer fluid
Turn and hold rear window wiper
switch1 in position2 or5
(
page 64) until the rear window is
clean.
The rear window wiper operates with
washer fluid.
For information on filling up the washer
reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 383).
Problems while driving
The engine runs erratically and misfires

An ignition cable may be damaged
(gasoline engine only).

The engine electronics may not be
operating properly.

Unburned gasoline may have entered
the catalytic converter and damaged it
(gasoline engine only).
Give very little gas.
Have the problem repaired by an
authorized Mercedes-Benz Light Truck
Center as soon as possible.The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle in a safe location as
soon as possible and turn off the en-
gine. Allow engine and coolant to cool
off.
Check the coolant level and add cool-
ant if necessary (
page 381).
164.boo Seite 65 Freitag, 30. März 2007 12:54 12

66 Getting started
Driving
In case of accident
If the vehicle is leaking fuel:
Do not start the engine under any
circumstances.
Notify local fire and/or police authori-
ties.
If the extent of the damage cannot be de-
termined:
Contact an authorized Mercedes-Benz
Light Truck Center or call Roadside
Assistance.
If no damage can be determined on the

major assemblies

fuel system

engine mount:
Start the engine in the usual manner.
164.boo Seite 66 Freitag, 30. März 2007 12:54 12