transmission MERCEDES-BENZ ML320 1997 Complete User Guide

168 Automatic transmission
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Selector lever position
The current selector lever position is indicated in the
gear range indicator display. The automatic gear
shifting process can be adapted to specific operating
conditions using the selector lever.Park position
The park position is to be used when parking the
vehicle. Engage only with the vehicle stopped.
The park position is not intended to serve as a
brake when the vehicle is parked. Rather, the
driver should always use the parking brake in
addition to placing the selector lever in park to
secure the vehicle.
Notes:
The key can only be removed from the steering
lock with the selector lever in position “P”. With
the key removed, the selector lever is locked in
position “P”.
With a malfunction in the vehicle’s electrical
system the selector lever could remain locked in
position “P”. To unlock the selector lever
manually, see page 259.
Reverse gear
Shift to reverse gear only with the vehicle
sto p ped .

169 Automatic transmission
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index 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 engage “N” while driving except to coast
when the vehicle is in danger of skidding (e.g. on
icy roads, see winter driving instructions on
page 180).
Important!
Coasting the vehicle, or driving for any other
reason with selector lever in “N” can result in
transmission damage that is not covered by the
Mercedes-Benz Limited Warranty.
The transmission automatically upshifts through
5th gear. Position “D” provides optimum driving
characteristics under all normal operating
conditions.Gear selection for special circumstances
The transmission gear ranges for special circumstances
can be selected by pressing the selector lever to the
right or the left with the selector lever in position “D”.
The gear range currently selected is indicated in the
instrument cluster display.
Briefly press selector lever in the çdirection:
The transmission downshifts, one gear at a time, in the
order “4”, “3”, “2”, “1”.
Press and hold selector lever in the çdirection:
The selector lever position display will switch to the
gear range currently selected by the automatic
transmission.
The transmission will only shift down one gear if the
gear range currently selected has already shifted to its
highest possible gear.
Briefly press selector lever in the ædirection:
The transmission will shift from the current gear range
to the next higher gear range. If the transmission is
already in gear range “D”, an additional upshift of one
gear is possible.

170 Automatic transmission
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Press and hold selector lever in the ædirection:
The transmission will shift from the current gear
directly to gear range “D”.
Important!
With transmission in gear range “D”, “4” or “3”,
upshifting from 1st to 2nd to 3rd gear is delayed
depending on vehicle speed and engine temperature.
This allows the catalytic converter to heat up more
quickly to operating temperatures.During the brief warm-up period this delayed upshift
and increased engine noise might be perceived as a
malfunction. However, neither the engine nor
transmission are negatively affected by this mode of
operation.
The delayed upshift is effective with vehicle speeds
below 31 mph (50 km / h) at partial throttle and engine
temperatures below 95°F (35°C).
To avoid overrevving the engine when the selector lever
is moved to a lower gear range, the transmission will not
shift to a lower gear, if the engine’s revolutions per
minute limit would be exceeded. In this case there will
be no downshift, even when the vehicle speed reaches
the engine’s RPM limit of that gear, e.g. by applying the
service brakes. Continue driving in the usual manner.
The transmission will then shift down automatically.
To prevent the engine from laboring at low RPM when
driving uphill gradients or with your vehicle heavily
loaded, the automatic transmission will downshift when
necessary to maintain engine RPM within the best
torque range.
Wa r n i n g !
On slippery road surfaces, never downshift in order
to obtain braking action. This could result in drive
wheel slip and reduced vehicle control. Your
vehicle’s ABS will not prevent this type of loss of
control.

171 Automatic transmission
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Gear ranges:
Upshift through 4th gear only. Suitable for
performance driving.
Upshift through 3rd gear only. Suitable for
moderately steep hills. Since the transmission
does not shift higher than 3rd gear, this gear
selection will allow use of the engine’s braking
power downhill.Upshift through 2nd gear only. For driving in
mountainous regions or under extreme operating
conditions. This gear selection will allow use of
the engine’s braking power when descending
steep grades.
Use this position, which makes maximum use of
the engine’s braking effect, while descending
very steep or lengthy downgrades and only at
speeds below 40 mph (60 km / h).

172 Automatic transmission
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Emergency operation (Limp home mode)
If vehicle acceleration worsens or the transmission no
longer shifts, the transmission is most likely operating
in Limp home mode which engages when there is a
malfunction of the transmission. This condition may be
accompanied by the “CHECK ENGINE” malfunction
indicator lamp in the instrument cluster coming on.
In this mode only the 2nd gear or reverse gear can be
activated.To engage 2nd gear or reverse:
1. Sto p t h e v e h i c l e .
2. Move selector lever to position “P”.
3. Turn off the engine.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Move selector lever to position “D” (for 2nd gear), or
move selector lever to position “R” (for reverse gear).
Have the transmission checked at your authorized
Mercedes-Benz Light Truck Center as soon as possible.

181 Driving instructions
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Winter driving
Have your vehicle winterized at your authorized
Mercedes-Benz Light Truck Center before the onset of
winter.
•Change the engine oil if the engine contains an oil
which is not approved for winter operation. For
viscosity (SAE / CCMC class) and filling quantity,
see page 292.
•Check engine coolant anticorrosion / antifreeze
concentration.
•Additive for the windshield washer and headlamp
cleaning system: Add MB Concentrate “S” to a
premixed windshield washer solvent / antifreeze
which is formulated for below freezing temperatures
see page 237.
•Test battery: Battery capacity drops with decreasing
ambient temperature. A well charged battery helps
to ensure that the engine can be started, even at low
ambient temperatures.
•Tires: We recommend M+S rated radial-ply tires on
all four wheels for the winter season. Observe
permissible maximum speed for M+S rated
radial-ply tires and the legal speed limit.In winter operation, the maximum effectiveness of the
antilock brake system (ABS), the four wheel electronic
traction system (4-ETS+), the electronic stability
program (ESP), and electronic brake proportioning
(EBP) can only be achieved with M+S rated radial-ply
tires and / or snow chains recommended by
Mercedes-Benz. Snow chains maximize performance.
For driving instructions using snow chains see
page 179.
Deep water
Caution!
Do not drive through flooded areas or water of unknown
depth. Before driving through water, determine its
depth. It should not be deeper than approximately
20 inches (50 cm).
If you must drive through deep water, drive slowly to
prevent water from entering the engine compartment or
passenger compartment, being ingested by the air
intake, possibly causing damage to electrical
components or wiring, to engine or transmission that is
not covered by the Mercedes-Benz Limited Warranty.

185 Driving instructions
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Driving on embankments, slopes and other steep
inclines should only be done straight up or downhill, i.e.
in the line of gravity.
Do not drive along the side of a slope (danger of vehicle
rollover). If in doing so, the vehicle begins to show a
tendency to roll, immediately steer into a line of gravity
(straight up or downhill).
To help avoid the vehicle rolling over, never turn it
around on steep inclines. If the vehicle cannot complete
the attempted climb, back it down in reverse gear.
Utilize the engine’s braking power when descending a
slope, observe the engine speed (do not overrev the
engine). Apply the service brake as needed.
Check the brakes after a lengthy downgrade drive.
Notes:
Avoid excessive engine speeds – drive with moderate
engine speeds (max. 3000 RPM).
Select gear range “2” or “1” on the automatic
transmission, see page 165.Traction in steep terrain:
Be easy on the accelerator and watch for continuous
wheel traction when driving in steep terrain.
The 4-ETS+ helps greatly when starting out on a steep
incline. The front wheels have then the tendency to slip
due to the weight reduction over the front axle. The ETS
recognizes the situation and limits the torque for the
front wheels by braking them. Simultaneously the
torque for the rear wheels is increased.
See page 203 for four wheel electronic traction system
(4-ETS+).
Driving across a hilltop:
To prevent the vehicle from speeding up too much after
climbing a hill, decelerate just ahead of a hilltop (do not
select gear range “N”). Use the momentum of the
vehicle to drive across the hilltop. Driving in this
manner prevents the vehicle from jumping across the
hilltop and thus loosing its forward momentum.

186 Driving instructions
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Driving downhill:
Select gear range “1” on the automatic transmission,
see page 165.
Drive downhill observing the same rules as driving
uphill.
Driving on embankments, slopes and other steep
inclines should only be done straight up or downhill, i.e.
in the line of gravity.
Do not drive along the side of a slope (danger of vehicle
rollover). If in doing so, the vehicle begins to show a
tendency to roll, immediately steer into a line of gravity
(straight up or downhill).Utilize the engine’s braking power when descending a
slope, observe the engine speed (do not overrev the
engine). Apply the service brake as needed.
The 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 the front
wheels when stopped, slide across a surface, thus loose
their ability to steer the vehicle.
Check the brakes after a lengthy downgrade drive.
Important!
Only apply the service brake if the vehicle travels
straight downhill, i.e. in the line of gravity.

188 Driving instructions
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Crossing obstacles:
Select gear range “1” on the automatic transmission,
see page 165.
Cross obstacles (e.g. tree stumps or big rocks) very
slowly by aiming one of the front wheels at the center of
the obstacle, and repeat same with the rear wheel.
Important!
Damage on the vehicle definitely increases the chance
for a subsequent accident.Notes:
Check the vehicle clearance before crossing obstacles
that possibly could damage the undercarriage.
If possible use the assistance of a second person.
Special attention is needed when crossing obstacles on
a steep incline. The vehicle could slide sideways as a
result of its possible slanted position.
Ruts:
Select gear range “1” on the automatic transmission,
see page 165.
A number of off-road tracks or other byways have deep
ruts which can cause the undercarriage to come in
contact with the ground.
Drive next to the ruts rather than through them if at all
possible.
Notes:
Check the vehicle clearance.
Damage on the vehicle definitely increases the chance
for a subsequent accident.

194 Driving instructions
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data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Tow in g a t r ai le r
There are many different laws, including speed limit
restrictions, having to do with trailer towing. Make sure
t ha t your rig will be lega l, not only for w here you reside,
but also for where you will be driving. A good source for
this information can be the police or local authorities.
Before you start driving with the trailer, check the
trailer hitch, break-away switch, safety chains, electrical
connections, lighting and tires. Also adjust the mirrors
to permit unobstructed view beyond rear of trailer.
If the trailer has electric brakes, start your vehicle and
trailer moving slowly, and then apply only the trailer
brake controller by hand to be sure the brakes are
working properly.
When towing a trailer, check occasionally to be sure that
the load is secure, and that lighting and trailer brakes
(if so equipped) are functioning properly.
Always secure items in the trailer to prevent load shifts
while driving.
Take into consideration that when towing a trailer, the
handling characteristics are different and less stable
from those when operating the vehicle without a trailer.
It is important to avoid sudden maneuvers.The vehicle and trailer combination is heavier, and
therefore is limited in acceleration and climbing ability,
and requires longer stopping distances. It is more prone
to reacting to side wind gusts, and requires more
sensitive steering input.
In order to gain skill and an understanding of the
vehicle’s behavior, you should practice turning,
stopping and backing up in an area which is free from
traffic.
If possible, do not brake abruptly, but rather engage the
brake slightly at first to permit the trailer to activate its
brake. Then increase the braking force.
Caution!
If the trailer should begin to sway, reduce the vehicle’s
speed and use the brake controller by hand to straighten
out the vehicle and trailer. In no case should you
attempt to straighten out the tow vehicle and trailer by
increasing the speed or oversteering and stepping on
the brakes.
If the transmission hunts between gears on inclines,
manually shift to a lower gear (select “4”, “3”, “2”
or “1”). A lower gear and reduction of speed reduces the
chance of engine overloading and / or overheating.