2003 MERCEDES-BENZ G55AMG engine

198 OperationDriving instructionsPower assistanceBrakesTo help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on and there is no audible warn-
ing (EBB), the brake fluid level in the
reservoir is too low.
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the res-
ervoir.
Have the brake system inspected at an au-
thorized Mercedes-Benz Light Truck Cen-
ter immediately.
All checks and service work on the brake
system should be carried out by an autho-
rized Mercedes-Benz Light Truck Center.
Install only brake pads and brake fluid
recommended by Mercedes-Benz.Warning!
G
When the engine is 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 stop or steer the vehi-
cle.Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components
or salty road conditions, the first braking ac-
tion may be somewhat reduced and in-
creased pedal pressure may be necessary to
obtain expected braking effect. Maintain a
safe distance from vehicles in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS) (
page 73).

199 Operation
Driving instructions
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so the air stream will cool down
the brakes faster.Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
When starting off on a slippery surface, do
not allow one drive wheel to spin for an ex-
tended period with the ESP switched off.
Doing so may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
To ensure sufficient traction during
off-road driving, activate differential locks
as needed (
page 145).
Parking
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.!When driving down long and steep
grades, relieve the load on the brakes
by selecting gear range3,2 or1 on the
automatic transmission to use the en-
gine’s braking power (
page 137).
This helps prevent overheating of the
brakes and reduces brake pad wear.
Warning!
G
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
To reduce the risk of personal injury as a re-
sult of vehicle movement, before
turning off
the engine and leaving the vehicle always:


Keep right foot on brake pedal.


Pull the parking brake lever up as many
notches as possible.


Move the selector lever to positionP.


Slowly release brake pedal.


When parked on an incline, turn front
wheel towards the road curb.


Turn the key to starter switch position0
and remove.


Take the key and lock vehicle when leav-
ing.

202 OperationDriving instructionsWinter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
move selector lever to positionN. Try to
keep the vehicle under control by correc-
tive steering action.Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
We therefore recommend depressing the
brake pedal periodically when traveling at
length on salt-strewn roads.
This can bring road salt impaired braking
efficiency back to normal. Be very careful
that you carry out these braking maneu-
vers without endangering any other road
users.
If the vehicle is parked after being driven
on salt-treated roads, the braking efficien-
cy should be tested as soon as possible af-
ter driving is resumed while observing the
safety rules in the previous paragraph.
For more information on winter driving
(
page 228).
iInformation on driving with snow
chains (
page 229).
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 control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km / h) vehicle
steering is adversely affected by the LOW
RANGE – ABS (
page 72).
Warning!
G
If the vehicle becomes stuck in snow, make
sure that snow is kept clear of the exhaust
pipe and from around the vehicle with the
engine running. Otherwise, deadly carbon
monoxide (CO) gases may enter vehicle in-
terior resulting in unconsciousness and
death.
To assure sufficient fresh air ventilation,
open a window slightly on the side of the ve-
hicle not facing the wind.Warning!
G
The outside temperature indicator is not de-
s i g n e d t o s e r v e a s a n i c e - w a r n i n g d e v i c e a n d
is therefore unsuitable for that purpose. In-
dicated temperatures just above the freez-
ing point do not guarantee that the road
surface is free of ice.

203 Operation
Driving instructions
Standing water
Passenger compartment
Off-road driving
!Do not drive through flooded areas or
water of unknown depth. Before driving
through water, determine its depth. It
should not be deeper than approxi-
mately 19 inches (48 cm).
If you must drive through standing wa-
ter, drive slowly to prevent water from
entering the passenger compartment
or the engine compartment. Water in
these areas could cause damage to
electrical components or wiring of the
engine or transmission, or could result
in water being ingested by the engine
through the air intake causing severe
internal engine damage. Any such dam-
age is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Always fasten items being carried as secure-
ly as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The rear cargo compartment is the preferred
place to carry objects. Always use partition
net when transporting cargo. Partition net
cannot secure hard or heavy objects. Al-
ways fasten items being carried as securely
as possible using the cargo tie-down rings in
the cargo area floor and fastening material.
Do not load items on the roof. It may cause
instability during some maneuvers which
could result in an accident. This vehicle is
not intended to carry items on its roof. Thus
roof rails and roof mounted ski or bike hold-
ers must not be used.
Warning!
G
Do not load items on the roof. It may cause
instability during some maneuvers which
could result in an accident.Warning!
G
Drive slowly in unknown terrain. This will
make it easier to recognize unexpected ob-
stacles and avoid damage to the vehicle.
To help avoid the vehicle rolling over, never
turn it around on steep inclines. If the vehi-
cle cannot complete the attempted climb,
back it down in reverse gear.
Do not drive along the side of a slope (dan-
ger of vehicle rollover). If in doing so the ve-
hicle begins to show a tendency to roll,
immediately steer into a line of gravity
(straight up or downhill).


205 Operation
Driving instructions
Checklist before off-road driving
Engine oil level

Check the engine oil level
(page 218). The display
ENGINE OIL
LEVEL - O.K.
must appear in the mul-
tifunction display.
Only then can the vehicle obtain a trou-
ble-free oil supply, even on steep gradi-
ents.
Tires


Check the tread depth and maintain
specified tire pressure (see tire pres-
sure label inside the fuel filler flap).


Check tires for possible damage and
remove foreign objects.


Replace missing valve caps.Rims


Dented or bent rims can cause tire
pressure loss and damage the tire
beads. For this reason, check and, if
necessary, change rims before driving
off-road.
Vehicle tool kit


Check if the vehicle jack is functional.


In all cases take the vehicle tool kit, a
strong tow rope, a shovel and a small
plank (to put under the vehicle jack on
sandy soil) with you.


Avoid excessive engine
speeds – drive at moderate engine
speeds (max. 3000 RPM).


Before driving through water, deter-
mine its depth.


Do not stop vehicle immersed in
water, and do not shut off the en-
gine.


Maintaining continuous and rea-
sonably vigorous accelerator appli-
cation when driving in sandy soil
will help overcome the vehicle roll-
ing resistance, and help to prevent
the vehicle from sinking into the
ground.


Do not initiate jumps with the vehi-
cle. It interrupts the forward mo-
mentum of the vehicle.


Always drive on slopes with the en-
gine running and the vehicle in
gear.


Inspect the vehicle for possible
damage after each off-road trip.

206 OperationDriving instructionsDriving in steep terrainSlope angle127°
236°

Comply with the warnings
(page 203) and rules for off-road
driving (
page 204).


Driving on embankments, slopes and
other steep inclines should only be
done straight up or downhill, i.e. in the
line of gravity. Maximum vehicle climb-
ing ability is a 80% grade.


Select gear range2 or1 on the auto-
matic transmission (
page 137).


Drive slowly.


Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overrev the en-
gine). Apply the service brake as need-
ed.


Check the brakes after a lengthy down-
grade drive.
Traction in steep terrain
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
select gear rangeN), to prevent the vehi-
cle from speeding up too much after climb-
ing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:


jumping across the hilltop


loosing its forward momentum.


speeding up too much after climbing
the hill.
iThe 4-ETS helps greatly when starting
out on a steep incline when the front
wheels have then the tendency to slip
due to the weight shifting away the
front axle.The 4-ETS recognizes the sit-
uation and limits the torque for the
front wheels by braking them. Simulta-
neously the torque for the rear wheels
is provided.

207 Operation
Driving instructions
Driving downhill

Select gear range1 on the automatic
transmission (
page 137).


Drive downhill observing the same
rules as driving uphill (
page 206).Driving through water
119 in (48 cm)


Before driving through water, deter-
mine its depth.
It should not be deeper than approxi-
mately 19 in (48 cm).


Comply with the warnings
(page 203) and rules for off-road
driving (
page 204).


Switch off the exterior lamps as well as
the climate control.


Select gear range2 or1 on the auto-
matic transmission (
page 137).


Enter the water only at a shallow spot,
driving at walking speed.


Do not stop vehicle immersed in water,
and do not shut off the engine.
There is a very high level of driving re-
sistance in water. The surface is slip-
pery and may not be firm, making
pulling away in water difficult and dan-
gerous.


Clean mud off the tire tread after driv-
ing through water.


To dry the brakes, apply pressure to the
brake pedal several times after leaving
the water.
!Only apply the service brake if the vehi-
cle travels straight downhill, i.e. in the
line of gravity.iThe special LOW RANGE – ABS 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 vehi-
cle.
!Never accelerate before driving into
the water. The bow wave could force
water into the engine and auxiliary
equipment, thus damaging them.

210 OperationDriving instructionsOff-road driving increases strain on the ve-
hicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:

Switch the transfer case in position
HIGH (
page 141).


Disengage differential locks
(page 146).


Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.


Inspect frame, oil pan, brake hoses,
etc., as well as vehicle underbody for
possible damage.


Check tires for possible damage and
remove foreign objects. Clean all exte-
rior lamps and conduct a brake test.


Clean all exterior lamps and check
them for possible damage.


Check for brush or branches caught in
the undercarriage.
They could increase the possibility of a
fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the
axles or drive shafts.


After continued operation in mud,
sand, water or other dirty conditions,
clean the brake discs, wheels, brake
pads and check and clean axle joints.


Conduct a brake test.Control and operation of radio trans-
mitters
COMAND, radio and telephone*Warning!
G
Do not forget that your primary responsibili-
ty is to drive the vehicle safely. Only operate
the COMAND, radio or telephone
1 if road,
traffic and weather conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km / h), your vehicle is
covering a distance of approximately
50 feet (approximately 14 m) every second.
1Observe all legal requirements.