2005 MERCEDES-BENZ G55AMG engine

150 Controls in detailAutomatic transmissionCanceling gear range limit
Press and hold the gear selector lever
in the D+direction until
Dreappears in
the multifunction display.
The transmission will shift from the current
gear range directly to gear rangeD.
Shifting into optimal gear range

Press and hold the gear selector lever
in the D-direction.
The transmission will automatically select
the gear range suited for optimal accelera-
tion and deceleration. This will involve
shifting down one or more gears.
Gear ranges
With the gear selector lever in positionD,
you can limit the transmission’s gear range
by pressing the gear selector lever to the
left (D-), and reverse the gear range limit
by pressing the gear selector lever to the
right (D+).
The selected gear range will appear in the
multifunction display. If you press on the
accelerator when the engine has reached
its rpm limit, the transmission will upshift
beyond any gear range limit selected.
!If the transfer case is in off-road driving
position LOW, the automatic transmis-
sion will not shift up automatically,
even when the engine has reached the
speed limit for that gear. There is a risk
of damaging the engine.
It is very important to make sure the
permissible engine speed is not ex-
ceeded.
Effect
é
The transmission shifts
through fourth gear only.
è
The transmission shifts
through third gear only.
With this selection you can
use the braking effect of the
engine.
ç
The transmission shifts
through second gear only.
Allows the use of engine’s
braking power when driving

on steep downgrades


in mountainous regions


under extreme operating
conditions
æ
The transmission operates in
first gear only.
For maximum use of engine’s
braking effect on very steep
or lengthy downgrades.

151 Controls in detail
Automatic transmission
Gear selector lever position
Effect
ì
Park position
Gear selector lever position
when the vehicle is parked. Place
gear selector lever in positionP
only when vehicle is stopped.
The park position is not intended
to serve as a brake when the
vehicle is parked. Rather, the
driver should always set the
parking brake in addition to
placing the gear selector lever in
positionP to secure the vehicle.
EffectThe SmartKey can only be
removed from the starter switch
with the gear selector lever in
positionP. With the SmartKey
removed, the gear selector lever
is locked in positionP.
If the vehicle’s electrical system
is malfunctioning, the gear
selector lever could remain
locked in positionP
(page 327).
í
Reverse gear
Place gear selector lever in
positionR only when vehicle is
stopped.
Effect
ë
Neutral
No power is transmitted from the
engine to the drive axle. When
the brakes are released, the
vehicle can be moved freely
(pushed or towed).
Do not engageN while driving
except:

to coast when vehicle is in
danger of skidding (e.g. on
icy roads) when the ESP is
deactivated or malfunction-
ing


when you have to shift the
transfer case
ê
Drive
The transmission shifts
automatically. All five forward
gears are available.

153 Controls in detail
Automatic transmission
Accelerator position
Your driving style influences the transmis-
sion’s shifting behavior:
Less throttle Earlier upshifting
More throttle Later upshifting
Kickdown
Use kickdown when you want maximum
acceleration.
Press the accelerator past the point of
resistance.
The transmission shifts into a lower
gear.

Ease on the accelerator when you have
reached the desired speed.
The transmission shifts up again.Emergency operation (Limp Home
Mode)
If vehicle acceleration worsens or the
transmission no longer shifts, the trans-
mission is most likely operating in limp
home (emergency operation) mode. In this
mode, only 2nd gear and reverse gear can
be activated.
Stop the vehicle.

Move gear selector lever toP.

Turn off the engine.

Wait at least ten seconds before re-
starting.

Restart the engine.

Move gear selector lever to positionD
(for second gear) orR.

Have the transmission checked at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.

154 Controls in detailTransfer caseFor more information on off-road driving,
see “Off-road driving” (
page 223).
Gear range
Switching transfer case
The switch is located in the center console.
1Transfer case indicator
2Gear range indicator
Transfer case indicator1 in the multi-
function display shows the gear position of
the transfer case.Switching from HIGH to LOW

Press upper half (“LOW”) of the trans-
fer case switch.
Once the shift is complete, gear
position
L is displayed in the transfer
case indicator.

Put gear selector in D.
H
HIGHRoad position
L
LOWOff-road position
This position is intended for driv-
ing off-road and step gradients.
The transmission will not upshift
automatically to the next higher
gear range when driving at the
rpm limit.The transfer case supports the
engine’s driving force (approx. 1/2speed). Output is therefore
increased.
N
NeutralNo power is transmitted from the
engine to the drive axle.
!The shift procedure can only be per-
formed when:

The engine is running.


The gear selector lever for the auto-
matic transmission is in positionN.


The vehicle is not at standstill.


The vehicle speed does not exceed
25 mph (40 km/h).
iIf the shift procedure does not take
place press upper half (“LOW”) of the
transfer case switch again.

155 Controls in detail
Transfer case
Switching from LOW to HIGH
Press lower half (“HIGH”) of the trans-
fer case switch.
Once the shift is complete, gear
position
H is displayed in the transfer
case indicator.

Put gear selector in D.Messages in the multifunction display
If a shift was not completed and the multi-
function display shows one of the following
messages:


TC SHIFT CONDITIONS NOT FULFILLEDThe shift did not take place. At least
one shift condition was not met.

Repeat the shift procedure.


TC IN NEUTRAL The shift did not take place. The trans-
fer case is in neutral. The gear
position
N is displayed in transfer case
indicator1.

Repeat the shift procedure.


TC SHIFT – CANCELLEDThe shift did not take place.

Repeat the shift procedure.


TRANSFER CASE – VISIT WORKSHOP!There may be a malfunction in the
system.

Repeat the shift procedure.

If the shift procedure still does not take
place, have the vehicle checked at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.
For more information, see “Practical hints”
section (
page 319).
!The shift procedure can only be per-
formed when:

The engine is running.


The gear selector lever for the auto-
matic transmission is in positionN.


The vehicle is not at standstill.


The vehicle speed does not exceed
40 mph (70 km/h).
iIf the shift procedure does not take
place press lower half (“HIGH”) of the
transfer case switch again.
Warning!
G
If TC is in neutral, transmission positionP
will not hold vehicle. The parking brake must
be applied to hold vehicle in place.
iIf the SmartKey is in starter switch
position0 or1, an alarm will sound if
the transfer case is in positionN and
the driver’s door is opened.
Engage transfer case to gear position
HIGH or LOW.

157 Controls in detail
Differential locks
A few words about differentials and differential locks
When a vehicle negotiates a turn, wheels
on the outside of the curve must travel far-
ther and rotate faster than the inside
wheels. The differential, the operation of a
set of gears that allows the powered
wheels in a vehicle to turn at different
speeds, makes this essential function pos-
sible.
The drawback is that the differential also
sends most of the engine’s power to the
wheel with the least load or strain on it. For
example, if one of a vehicle’s powered
wheels sits on a patch of snow and spins
because there is no traction, all of the en-
gine’s power will go to that wheel because
the power will take the path of least resis-
tance. Meanwhile, the opposite wheel, sit-
ting on dry pavement where it could get
enough grip to start the vehicle moving,
sits idle because it receives no power.The Electronic Traction System (ETS) ad-
dresses this problem and provides for
good control and steering ability by auto-
matically slowing the slipping wheel and
thus increasing the power to the other
non-slipping drive wheels to get the vehicle
moving. The ESP and ETS in this vehicle
feature such intelligent limited-slip differ-
ential technology, ideally suited for
on-road and light off-road driving. Transfer
case position LOW (
page 154) also en-
hances off-road driving capabilities
(
page 223).
More extreme off-road conditions may call
for another solution, engaging a differen-
tial lock or preventing the differential from
operating altogether. As part of its stan-
dard equipment, this vehicle comes with
three differential locks: front, transfer case
(center) and rear. Each can be engaged
simply by pushing dashboard-mounted
buttons in sequential order (center, rear,
front) (
page 158). When the transfer
case (center) differential is locked, half of
the engine’s power is automatically distrib-
uted to the front wheels and half to the rear wheels. When the rear differential is
locked, power going to the rear wheels is
equally distributed, so that both rear
wheels turn at the same speed and torque.
When the front differential is locked, all
four wheels now turn with equal power and
torque. Please be aware that engaging the
differential locks will significantly reduce
the steering ability of the vehicle.
For your safety and the safety of others
and to prevent damage to the vehicle, the
differential locks must not be engaged
when driving on paved roads. It is impor-
tant to understand that during
on-road/paved driving, differentials are
absolutely necessary for providing the es-
sential control and steering ability of the
vehicle. The differential locks, therefore,
must not be engaged when driving on
paved roads and should only be used to
the extent necessary to negotiate off-road
conditions which cannot be handled by the
systems (automatic 4-ETS, the ESP, manu-
al switch position “LOW” of transfer case)
this vehicle comes equipped with.

165 Controls in detail
Climate control
Climate control panel
1
Windshield defroster air vents
2
Center air vent, adjustable
3
Thumbwheel for center air vent
4
Side air vent, adjustable
5
Side defroster air vent, fixed
6
Thumbwheel for side air vent
7
Footwell air vents
8
Climate control paneliFor draft-free ventilation, move the
sliders for the center air vents to the
middle position.
1
Air volume
2
Temperature control, left
(driver side)
3
Temperature control, right
(passenger side)
4
Air distribution control
5
Rear window defroster (
page 163)
6
AC cooling on / off (AC
OFF
)
Residual engine heat utilization
(REST)
7
Air distribution and air volume
(automatic mode)
8
Air recirculation
9
Defrosting

166 Controls in detailClimate controlThe climate control is operational whenev-
er the engine is running. You can operate
the climate control system in either the au-
tomatic or manual mode. The system cools
or heats the interior depending on the se-
lected interior temperature and the cur-
rent outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the AC
OFF
mode is selected
(
page 170).
Setting the temperature
Use temperature controls2 and3 to
separately adjust the air temperature on
each side of the passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C).
Warning!
G
When operating the climate control, the air
that enters the passenger compartment
through the air vents in the footwell can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite on unprotected skin in the immediate
area of the air vents. Always keep sufficient
distance between unprotected parts of the
body and the footwell air vents. If necessary,
change the air flow using the air distribution
controls to direct the air away from the foot-
well air vents (
page 167).
Warning!
G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.iIf the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
iWhen operating the climate control
system in automatic mode, you will
only rarely need to adjust the tempera-
ture, air volume, and air distribution.