Page 49 of 342
46 Seats
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Heated seats (optional on ML 320)
The seat heater switches are located on the center
console.
The seat heaters can be switched on with the engine
running.Press switch to turn on seat heater:
1Normal seat heating mode. One indicator lamp in
the switch lights up.
2Rapid seat heating mode. Both indicator lamps in
the switch light up.
After approximately 5 minutes in the rapid seat
heating mode, the seat heater automatically
switches to normal operation and only one indicator
lamp will stay on.
Turning off seat heater:
If one indicator lamp is on, press upper half of switch.
If both indicator lamps are on, press lower half of
switch.
If left on, the seat heater automatically turns off after
approximately 20 minutes of operation.
P54.25-2036-26
12
Page 79 of 342

76 Rear view mirrors
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Automatic (optional on ML 320):
With the key in steering lock position 2 and the
automatic antiglare function activated, the mirror
reflection brightness responds to changes in light
sensitivity.
To a c ti va te :
Press button (1). The green indicator lamp in the inside
rear view mirror lights up.To d e a c t i va t e :
Press button (1) again. The indicator lamp in the inside
rear view mirror goes out. The mirror brightness does
not respond to changes in light sensitivity.
Notes:
With gear selector lever in position “R”, or with the
interior lamps (except cargo compartment lamp)
switched on, the mirror brightness does not respond to
changes in light sensitivity.
The automatic antiglare function does not react, if
incoming light is not aimed directly at sensors in the
inside rear view mirror.
The antiglare function will not react for example, if the
cargo area is fully loaded.
Wa r n i n g !
In the case of an accident liquid electrolyte may
escape the mirror housing when the mirror glass
breaks.Electrolyte has an irritating effect. Do not allow the
liquid come into contact with eyes, skin, clothing,
or respiratory system. In cases it does, immediately
flush affected area with water, and seek medical
help if necessary.
Page 83 of 342
80 Rear view mirrors
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Driver’s side exterior rear view mirror, antiglare
mode (optional on ML 320)
Antiglare mode:
With the key in steering lock position 2, the mirror
reflection brightness responds to changes in light
sensitivity.
With the gear selector lever in position “R”, or with the
interior light switched on, the mirror brightness does
not respond to changes in light sensitivity.Note:
The automatic antiglare function does not react, if
incoming light is not aimed directly at sensors in the
inside rear view mirror.
The antiglare function will not react for example, if the
cargo area is fully loaded.
Page 95 of 342

92 Trip computer
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
To calibrate the compass:
If the vehicle was exposed to a significant magnetic
zone, such as high voltage power lines, the compass
may have to be calibrated.
Calibration of the compass should be done in an area
free of steel superstructures and power lines. All
electrical consumers (e.g. exterior lamps, climate
control, rear window defroster etc.) should be switched
off, doors and liftgate closed. Do not open or close the
roof. An open liftgate triggers the display “–––”.
1. Start and run the engine.
2. Press MODE key repeatedly until the compass
display appears in the trip computer display.
3. Press RESET key and afterwards press MODE key,
“CAL–” appears in the display.4. Press and hold RESET key for a minimum of
2 seconds, to access the calibration mode.
The display shows “CAL”.
5. Without interruption drive two full circles at a speed
between 3 mph (5 km / h) and 7 mph (10 km / h).
The message “CAL” goes out after a short time.
6. The calibration of the compass is now complete.
Note:
If “CAL” remains in the display, calibration was not
successfully completed. To recalibrate, remove key from
the steering lock. Insert key, start the vehicle and start
the calibration procedure.
We recommend that you have the compass calibrated at
a Mercedes-Benz Light Truck Center.
Page 102 of 342

99 Exterior lamp switch
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Headlamp mode
The headlamps can be switched on and off manually or
automatically.
Manual operation:
The low beam headlamps and parking lamps can be
switched on and off with the exterior lamp switch. For
exterior lamp switch, see page 97.
Automatic operation:
With electronic key in steering lock in position 1 turn
exterior lamp switch to positionU.
The parking lamps switches on and off automatically
depending on the brightness of the ambient light.With the engine running and exterior lamp switch in
positionU:
USA only:
The low beam headlamps and parking lamps are
switched on and off automatically depending on the
brightness of the ambient light.
Canada only:
In conjunction with the daytime running lamps, see
page 100, in low ambient light conditions the parking
lamps will also switch on.
Note:
The high beam headlamps, high beam flasher, low beam
headlamps, parking lamps can still be switched on and
off manually using the exterior lamp switch.
The headlamps will not be automatically switched on
under foggy conditions.
Front fog lamps and rear fog lamps cannot be switched
on manually with exterior lamp switch in positionU.
To activate the fog lamps turn exterior switch to
positionB.
Wa r n i n g !
The driver is responsible for the operation of the
vehicle’s lights at all times. The automatic
headlamp feature is only an aid to the driver.
Switch on the vehicle lights by hand when driving
or traffic conditions require you to do so.
Page 103 of 342
100 Exterior lamp switch
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Daytime running lamp mode (Canada only)
Turn exterior lamp switch to positionD.
When the engine is running the low beam headlamps
are automatically switched on. In low ambient light
conditions the parking lamps will also switch on.
When shifting from a driving position to position “N”
or “P”, the exterior lamps switches off (3 minutes delay).For nighttime driving the exterior lamp switch should
be turned to position õ or U to permit activation
of the high beam headlamps.
Note:
The high beam flasher is always available.
Page 105 of 342

102 Exterior lamp switch
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Setting illumination time:
The illumination time can only be set while the vehicle
is at a standstill and the electronic key in steering lock
position 2.
1. Turn exterior lamp switch to positionD.
2. Press top (1) of fog lamp switch (approx. 5 seconds),
until the clock display (located in the instrument
cluster) displays the actual illumination time.3. Continued pressing of the switch varies the
illumination time between 0 (off) and 60 seconds.
Each time the switch is pressed, the illumination
time increases by 15 seconds.
4. Approx. 5 seconds after pressing the switch the
illumination time is set and the clock is again
displayed.
Locator lighting
This function will be only active with exterior lamp
switch in positionU.
After unlocking the vehicle with the electronic key
during darkness, parking lamps and fog lamps switch
on for approximately 40 seconds.
The exterior lamps will be switched off when opening
the driver’s door.
Page 114 of 342

111 Automatic climate control
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Automatic climate control
The automatic climate control only operates with the
engine running.
The system is always at operational readiness, except
when manually switched off.
In the automatic mode the automatic climate control
cools or heats the interior depending on outside
temperature and the selected interior temperature.
Make the temperature settings in small increments.
If the vehicle interior has been heated by direct sunlight
and is very hot, ventilate the interior (open door or
windows for a short period) before driving off
Keep the air intake grill in front of the windshield free
of debris and snow.
The air conditioning mode removes considerable
moisture from the air during operation in the cooling
mode. It is normal for water to drip on the ground
through ducts in the underbody.
If the economy mode AC
OFF
is selected, the air
conditioning compressor will not engage and it is not
possible to air condition in this setting. See page 117.Notes:
The interior temperature sensor (10) should not be
touched to maintain a precise temperature.
If the vehicle travels from shade into direct sunlight, a
sensor automatically increases the air volume
temporarily to maintain the interior temperature.
The automatic climate control will not remove moisture
from the air at low outside ambient temperatures.
The air conditioner switches itself off for its own
protection if refrigerant is lost. No cooling will then take
place. Economy mode AC
OFF
cannot be switched off.
Have the air conditioner checked by a Mercedes-Benz
Center should this happen.
Dustfilter
Nearly all dust particles and pollen are filtered out
before outside air enters the passenger compartment
through the air distribution system.
Severe conditions (e.g. strong air pollution) may require
replacement of the filter before its scheduled interval.
A clogged filter will reduce the air volume to the
interior.