Transmission not shifting MERCEDES-BENZ ML320 2002 W163 Owner's Manual

184 Automatic transmission
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Driving
The selector lever is automatically locked while in
position “P”. To move the selector lever out of
position “P”, the service brake pedal must be firmly
depressed before the shift lock will release.
Shift selector lever to the desired position only when the
engine is idling normally and the service brake is
applied. Do not release the brake until ready to drive.
The vehicle may otherwise start creeping when the
selector lever is in drive or reverse position.Important!
After selecting any driving position from “N” or “P”,
wait a moment to allow the gear to fully engage before
accelerating, especially when the engine is cold.
Accelerator position
Partial throttle = early upshifting = normal acceleration
Full throttle = later upshifting = rapid acceleration
Kickdown (depressing the accelerator beyond full
throttle) = downshifting to a lower gear = maximum
acceleration. Once the desired speed is attained, ease up
on the accelerator – the transmission shifts up again.
Stopping
For brief stops, e.g. at traffic lights, leave the
transmission in gear and hold vehicle with the service
brake.
For longer stops with the engine idling, shift into “N”
or “P” and hold the vehicle with the service brake.
When stopping the vehicle on an uphill gradient, do not
hold it with the accelerator, use the brake. This avoids
unnecessary transmission heat build up.
Wa r n i n g !
It is dangerous to shift the selector lever out of “P”
or “N” 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.

185 Automatic transmission
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Maneuvering
To maneuver in tight areas, e.g. when pulling into a
parking space, control the vehicle speed by gradually
releasing the brakes. Accelerate gently and never
abruptly step on the accelerator.
To rock a vehicle out of soft ground (mud or snow),
alternately shift from forward to reverse, while applying
slight partial throttle.
Rocking a vehicle free in this manner may cause the
ABS or traction system malfunction indicator lamp to
come on. Turn off and restart the engine to clear the
malfunction indication.Towing a trailer
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.
At very steep inclines, not manageable with selector
lever in position “1”, switch transfer case to LOW
RANGE, see page 227 for instructions on how to engage
LOW RANGE.
For instructions on trailer towing refer to page 209.
Wa r n i n g !
Getting out of your vehicle with the selector lever
not fully engaged in position “P” is dangerous.
Also, when parked on an incline, position “P” alone
may not prevent your vehicle from moving,
possibly hitting people or objects.Always set the parking brake in addition to shifting
to position “P”, see page 191 for parking brake. When parked on an incline, also turn front wheel
against curb.
Wa r n i n g !
When leaving the vehicle always remove the key
from the steering lock, and lock the vehicle. Do not
leave children unattended in the vehicle, or with
access to an unlocked vehicle. Children could move
the gear selector lever from position “P”, which
could result in an accident or serious injury.

186 Automatic transmission
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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 281.
Reverse gear
Shift to reverse gear only with the vehicle
stopped.

187 Automatic transmission
Te ch n i c a l
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 199).
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 “D –” direction:
The transmission will shift from the current gear range
to the next lower gear range.
Press and hold selector lever in the “D –” direction:
The selector lever position display will switch to the
gear range currently selected by the automatic
transmission.
Shifting into another gear range that allows for quicker
acceleration or to slow the vehicle down is possible.
Downshifts can also be performed.
Note:
To avoid overrevving the engine when the selector lever
is moved in “D –” direction, the transmission will not
shift to a lower gear range if the engine’s revolutions
per minute limit would be exceeded.

188 Automatic transmission
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Briefly press selector lever in the “D +” direction:
The transmission will shift from the current gear range
to the next higher gear range.
Press and hold selector lever in the “D +” direction:
The transmission will shift from the current gear range
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 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.

204 Driving instructions
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data Instruments
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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 183.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 when the front wheels have then the tendency to
slip due to the weight shifting away the front axle.
The 4-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 221 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.

256 Engine compartment
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Automatic transmission fluid level
The transmission has a permanent fill of automatic
transmission fluid.
Regular automatic transmission fluid level checks and
changes are not required. For this reason the dipstick is
omitted.
If you notice fluid leaks or gear shifting malfunctions,
have your authorized Mercedes-Benz Light Truck Center
check the transmission fluid level.
Engine oil consumption
Engine oil consumption checks should only be made
after the break-in period. During the break-in period,
higher oil consumption may be noticed and is normal.
Frequent driving at high engine speeds results in
increased consumption.Coolant level
To check the coolant level, the vehicle must be parked
on level ground and the engine stopped.
Check coolant level only when coolant is cold.
The coolant level should reach the COLD LEVEL mark in
the reservoir.P20.30-0241-20