2008 MERCEDES-BENZ GL550 ABS

356 Operation
Driving instructions
Read this chapter carefully before you be-
gin off-road travel.
Familiarize yourself with the vehicle char-
acteristics and gear changing before you
attempt any difficult terrain off-road driv-
ing. We recommend that you start out with
easy off-road travel.Special driving features for off-road
driving
The following driving features are available
for specific kind of operation:

Off-road – ABS (page 102)

Off-road – ESP® (page 106)

Off-road – 4-ETS (page 108)

Hill start assist system (page 196)

LOW RANGE mode* (page 201)

Differential locks* (page 204)

Downhill Speed Regulation (DSR)
(
page 273)

Off-road driving program (Vehicles
without enhanced off-road package*)
(
page 277)

Air suspension (page 278)Off-road driving rules

Engage the off-road driving program
(
page 277) or LOW RANGE mode*
(
page 201) before driving under
off-road conditions.

If necessary, activate differential
locks* (
page 204).

Make sure you select a vehicle level
(
page 279) appropriate to the topo-
graphical conditions. Always make
sure the vehicle has enough ground
clearance.

Fasten items being carried as securely
as possible (
page 295).

Always navigate gradients with the en-
gine on and with the transmission en-
gaged in a gear. Switch on the DSR
(
page 274) to help maintain a preset
speed.
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360 Operation
Driving instructions
Driving downhill

Drive slowly.

Do not drive at an angle to the incline.
Steer into the line of gravity and drive
with the front wheels pointing straight
downhill. Otherwise, the vehicle may
slide sideways off the path and roll
over.

Shift automatic transmission to
position1 (
page 197).

On steep inclines, use the Downhill
Speed Regulation (
page 273).

Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brake
gently. Make sure the vehicle is moving
in the line of gravity.

Check the brakes after a lengthy down-
grade drive.Driving through water
1Fording depth

Before driving through water, deter-
mine its depth.
iThe special Off-road – ABS (page 102)
setting allows for precise and brief (cyclical)
blocking of the front wheels, permitting them to
dig into loose ground.
Remember that, when stopped, the front wheels
slide across a surface and thus lose their ability
to steer the vehicle.Vehicles with air
suspension
program1
Raised level20.00 in (50 cm)
Vehicles with
enhanced off-road
package*1
Off-road 3 level23.60 in (60 cm)
Off-road 2 level20.00 in (50 cm)
Off-road 1 level20.00 in (50 cm)
!The water depth must not exceed the
respective value listed in the table. The ground
under the water might not be firm which could
result the water being deeper than expected
when driving the vehicle through it. Please note
that the water level is correspondingly lower for
flowing water.
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410 Operation
Tires and wheels
Load identification
1Load identificationIn addition to tire load rating, special load
identification1 may be molded into the
tire sidewall following the letter designat-
ing the tire speed rating (
page 406).
No specification given: absence of any text
(like in above example) indicates a
standard load (SL) tire.
XL or Extra Load: designates an extra load
(or reinforced) tire.
Light Load: designates a light load tire.
C, D, E: designates load range associated
with the maximum load a tire can carry at
a specified pressure.
DOT, Tire Identification Number (TIN)
U.S. tire regulations require each new tire
manufacturer or tire retreader to mold a
TIN into or onto a sidewall of each tire
produced.
The TIN is a unique identifier which facili-
tates efforts by tire manufactures to notify
purchasers in recall situations or other
safety matters concerning tires and gives
purchasers the means to easily identify
such tires.
The TIN is comprised of “Manufacturer’s
identification mark”, “Tire size”, “Tire type
code” and “Date of manufacture”.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.
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420 Operation
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:

Check of anticorrosion and antifreeze
concentration.

Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“MB SummerFit” to a premixed wind-
shield washer solvent/antifreeze
which is formulated for temperatures
below freezing point (
page 569).

Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started
even at low ambient temperatures.

Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately
1/6in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Not all M+S rated
tires provide special winter performance.
Make sure the tires you use show the
mountain/snowflake.marking on the
tire sidewall. These tires meet specific
snow traction performance requirements
of the Rubber Manufacturers Association
(RMA) and The Rubber Association of Can-
ada (RAC) and have been designed specif-
ically for use in snow conditions. Use of
winter tires is the only way to achieve the
maximum effectiveness of the ABS, ESP
®,
4-ETS, and EBP in winter operation.
For safe handling, make sure all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available from your tire
dealer or from any authorized
Mercedes-Benz Light Truck Center.
Warning!G
Winter tires with a tread depth of less than 1/6in (4 mm) must be replaced. They are no
longer suitable for winter operation.
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436 Practical hints
What to do if …
Lamps in instrument clusterGeneral information:
If any of the following lamps in the instru-
ment cluster fails to come on during thebulb self-check when switching on the
ignition, have the respective bulb checked
and replaced if necessary.
ProblemPossible cause/consequenceSuggested solution
-The yellow ABS indicator lamp
comes on while the engine is
running.ABS has detected a malfunction and has
switched off. The BAS, ESP®, EBP, and 4-ETS
are also switched off (see messages in multi-
function display).
The brake system is still functioning normally
but without the ABS available.
If the ABS control unit is malfunctioning,
other systems such as the navigation
system* or the automatic transmission may
also be malfunctioning.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the
multifunction display (
page 449).
Have the system checked at an
authorized Mercedes-Benz Light
Truck Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
The charging voltage has fallen below
10 volts. The ABS has switched off.
The battery might not be charged sufficiently.When the voltage is above this value
again, the ABS is operational again and
the ABS indicator lamp should go out.
If the ABS indicator lamp does not go out:
Have the generator (alternator) and
the battery checked.
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437 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested solution
-The yellow ABS indicator lamp comes on while
the engine is running.The self-diagnosis has not yet
been completed yet.The display will clear after driving a short
distance at a vehicle speed of above
12 mph (20 km/h).
;(USA only)
3(Canada only)
The red brake warning lamp
comes on while driving and an
acoustic warning sounds.You are driving with the
parking brake set.Release the parking brake
(
page 59).
There is insufficient brake fluid
in the reservoir.Risk of accident! Carefully stop the
vehicle in a safe location or as soon as
it is safe to do so.
Apply the parking brake (page 67).
Contact an authorized
Mercedes-Benz Light Truck Center.
Do not add brake fluid! This will not
solve the problem.
Warning!G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on.
Do not add brake fluid before checking the
brake system. Overfilling the brake fluid res-
ervoir can result in spilling brake fluid on hot
engine parts and the brake fluid catching
fire. You can be seriously burned.!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks.
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438 Practical hints
What to do if …
ProblemPossible cause/conse-
quenceSuggested solution
;(USA only)
3(Canada only)
-
v
The red brake warning lamp
comes on while driving. In
addition, the yellow ABS mal-
function indicator lamp, and
the yellow ESP
® warning lamp
come on and an acoustic warn-
ing sounds.
The Electronic Brake Propor-
tioning (EBP) has switched off
due to a malfunction.
The ABS, the BAS, and the
ESP
® are also switched off.
Have the system checked at an autho-
rized Mercedes-Benz Light Truck
Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
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451 Practical hints
What to do if …
Text messages
Display messagePossible cause/consequencePossible solution
ABSABS, ESP Inoperative
See Operator’s ManualThe ABS and the ESP® have been
switched off due to a malfunction.
The BAS is also switched off.
The brake system is still functioning
normally but without the ABS avail-
able.Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
Failure to follow these instructions increases
the risk of an accident.
ABS, ESP Unavailable
See Operator’s ManualThe ABS and the ESP® have been
switched off because of insufficient
power supply. The charging voltage
has fallen below 10 volts.
The BAS is also switched off.
The brake system is still functioning
normally but without the ABS
available.When the voltage is above this value again, the
ABS is operational again and the message in
the multifunction display should disappear.
If the message in the multifunction display
does not disappear:
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
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