2008 MERCEDES-BENZ ML550 heating

287 Controls in detail
Useful features
Switch on the ignition (page 40).
1Cigarette lighter
Open the ashtray (page 285).
Push in cigarette lighter1.
The cigarette lighter will pop out auto-
matically when hot.
Power outlets!The lighter socket can accommodate
12V DC electrical accessories (up to a maximum
of 180 W) designed for use with the standard
“cigarette lighter” plug type. Keep in mind, how-
ever, that connecting accessories to the lighter
socket (for example extensive connecting and
disconnecting, or using plugs that do not fit prop-
erly) can damage the lighter socket. With the
socket damaged, the lighter may no longer be
able to be placed in the heating (pushed-in) posi-
tion, or the lighter may pop out too early with the
lighter not hot enough.
To help avoid damaging the cigarette lighter
socket, we recommend connecting 12V DC elec-
trical accessories designed for use with the stan-
dard “cigarette lighter” plug type to the 12V
power outlets (
page 287) in your vehicle
whenever possible.
iIf the engine is off, and the cigarette lighter
is being used extensively, the vehicle battery
may become discharged.
!If you use all power outlets in the vehicle,
make sure that the maximum current drawn
does not exceed 55 A.
iThe power outlets can be used to
accommodate 12V DC electrical accessories
(e.g. air pump, auxiliary lamps) up to a maximum
of 240 W.
If the engine is off, the battery may become dis-
charged if used for long periods of time.
iYou can use the power outlets, except for
the power outlet in the front center console,
even if the ignition is switched off.
An emergency shut-off feature ensures that the
vehicle’s electrical voltage does not fall below a
minimum level. If the voltage drops to this mini-
mum level, the power outlets are automatically
switched off. This ensures that enough power re-
mains to start the engine.

290 Controls in detail
Useful features
Heated steering wheel*
The steering wheel heating warms up the
leather area of the steering wheel.
The stalk is on the lower left-hand side of
the steering wheel.
1Switching on
2Indicator lamp
3Switching offSwitching on
Switch on the ignition (page 39).
Turn switch at the tip of stalk in the
direction of arrow1.
The steering wheel is heated. Indicator
lamp2 comes on.Switching off
Turn switch at the tip of stalk in the
direction of arrow3.
The heated steering wheel is switched
off. Indicator lamp2 goes out.
For information on the steering wheel, see
“Multifunction steering wheel”
(
page 148).
iThe steering wheel heating is turned off tem-
porarily and the indicator lamp2 remains on
when

the temperature of the vehicle interior is
above 86°F (30°C)

the temperature of the steering wheel is
above 95°F (35°C)
When these conditions do not apply anymore,
steering wheel heating continues.
iIndicator lamp2 flashes or goes out

in case of power surge or undervoltage

in case of a steering wheel heating malfunc-
tion
iThe steering wheel heating switches off
automatically when you remove the SmartKey
from the starter switch or, on vehicles with
KEYLESS-GO*, when you switch off the ignition
(
page 39) and open the driver’s door.

312 Operation
Driving instructions
Power assistance
BrakesTo 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.
Warning!G
With the engine 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 brake and steer the ve-
hicle.
Warning!G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat re-
duced and increased pedal pressure may be
necessary to obtain expected braking ef-
fect. 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.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.

313 Operation
Driving instructions
Refer to the description of the Brake Assist
System (BAS) (
page 100).
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the
reservoir.
The brake fluid level in the reservoir may
be too low if the brake warning lamp in the
instrument cluster comes on and an
acoustic warning sounds although the
parking brake is released (
page 401).
Observe additional messages in the multi-
function display that may appear
(
page 430).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Light Truck Center.All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Light Truck Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
park, so that the air stream will cool down
the brakes faster.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
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 shifting into a
lower gear to use the engine’s braking power.
This helps prevent overheating of the brakes and
reduces brake pad wear.
When using the engine’s braking power, a drive
wheel may not spin for an extended period of
time, e.g. on slippery road surfaces. This may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.

332 Operation
Driving instructions

Adjust the mirrors (page 49) 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 make sure the
brakes are working properly.

Always secure items in the trailer to
prevent load shifts while driving.

When towing a trailer, check occasion-
ally to make sure the load is secure,
and that lighting and trailer brakes (if
so equipped) are functioning properly.

Take into consideration that when tow-
ing a trailer, the handling characteris-
tics are different and less stable from
those when operating the vehicle with-
out a trailer.
It is important to avoid sudden maneu-
vers.

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
It is more prone to reacting to cross
wind gusts, and requires more sensi-
tive steering input.

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.

If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(
page 192).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.

On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(
page 253).

When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.

If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.
!If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.

339 Operation
At the gas station
Low outside temperatures
(diesel engine)
To prevent malfunctions, diesel fuel with
improved cold flow characteristics is of-
fered in the winter months. Check with
your fuel retailer.Check regularly and before a long trip
Open the hood (page 341).
Example illustration ML 320 CDI (ML 350,
ML 550, ML 63 AMG similar)
1Brake fluid
2Coolant level
3Windshield washer system and
headlamp cleaning system*
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 343).
iDiesel engine:
If you have driven the vehicle until the tank is
empty, the fuel system needs to be bled
(
page 488).
!Diesel engine:
The engine is more susceptible to wear and
damage if you use

marine diesel fuel

heating oil

additives
The exhaust aftertreatment device will be
seriously damaged if you use

LOW SULFUR HIGHWAY DIESEL FUEL
(500 ppm SULFUR MAXIMUM)

any other diesel fuel with a sulfur content of
above 15 ppm
The use of such non-approved fuels and/or
special additives is not covered by the
Mercedes-Benz Limited Warranty.
!Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosine. The
fuel system and engine will otherwise be dam-
aged, which is not covered by the
Mercedes-Benz Limited Warranty.

419 Practical hints
What to do if …
Display messagePossible cause/consequencePossible solution
ESPUnavailable
See Operator’s ManualThe ESP® was deactivated because
of insufficient power supply. The
charging voltage has fallen below
10 volts.
The brake system is still functioning
normally but without the ESP
®
available.
When the voltage is above this value again, the
ESP® is operational again and the message in
the multifunction display should disappear.
If the message in the multifunction display does
not disappear:
Have the generator (alternator) and the
battery checked.
Have the system checked at an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
If the yellow ESP® warning
lampv flashes while driving and
this message appears, the 4-ETS has
switched off to prevent overheating
of the drive wheel brakes.As soon as the brakes have cooled off, the
4-ETS switches on again.
The message in the multifunction display disap-
pears and the ESP
® warning lampv goes
out.
The self-diagnosis has not been
completed yet.The display will clear after driving a short
distance at a vehicle speed of above
12 mph (20 km/h).

539 Index
G
Garage door opener 302
Gasoline see Fuel
GAWR 380
Gear range
Automatic transmission 192
Limiting 192
Shifting into optimal 194
Gear selector lever 25, 54, 183
Cleaning 397
Gearshift pattern 183
Messages in the multifunction
display 420
Position 186
Shifting procedure 186
Transmission position 187
Global locking/unlocking see Key,
SmartKey
Glove box 279
Good visibility 199
Gross Axle Weight Rating see GAWR
Gross Trailer Weight see GTW
Gross Vehicle Weight Rating see GVWR
Gross Vehicle Weight see GVWGTW 380
GVW 380
GVWR 380
H
Halogen headlamp see Headlamps
Hands-free microphone 33
Hard plastic trim items, cleaning 396
Hazard warning flasher 141
Head restraints 44, 127
Active head restraint 88, 127
Front seats, Adjusting 44
Rear seats 89
Rear seats, Adjusting 128
Rear seats, Removing and
installing 128
Headlamp aim
Adjusting 473
Headlamp cleaning system* 199, 346
Headlamp shut-off delay see Delayed
shut-off, Exterior lampsHeadlamps
Automatic headlamp mode 136
Bi-Xenon* 438, 467
Cleaning lenses 393
Cleaning system* 199, 346
Halogen 466
High beam see High beam flasher
High beam see High beam headlamps
Light sensor, Messages in the
multifunction display 438
Low beam see Low beam headlamps
Manual headlamp mode 136
Messages in the multifunction
display 438, 439, 440, 441, 442,
443
Replacing bulbs 463, 464
Switch 59, 135
Heated seats see Seat heating*
Heated steering wheel* 290
Height adjustment
Vehicle level control (Vehicles with
Air suspension program*) 257