2008 MERCEDES-BENZ ML320 check engine

325 Operation
Driving instructions

Before driving through water, deter-
mine its depth.

Vehicles with air suspension program*:
Select the highest vehicle level
possible (
page 255).

Switch to off-road driving program
(
page 253) before driving through
water.

Shift automatic transmission to
position1 or2 (
page 192).

Avoid high engine speeds.

Enter and leave the water only at a
shallow spot, driving at walking speed.

Drive through the water slowly and at a
constant speed.

Do not stop vehicle while immersed in
water, and do not shut off the engine.

There is a very high level of driving re-
sistance in water. The surface is slip-
pery and may not be firm, making
pulling away in water difficult and dan-
gerous.

Make sure that only small bow waves
are formed when driving the vehicle
through water.

Clean mud off the tire tread after driv-
ing through water.

To dry the brakes, apply pressure to the
brake pedal several times while driving
after leaving the water.Crossing obstacles
!The water depth must not exceed the
respective value listed in the table. The ground
under the water might not be firm which could
result the water being deeper than expected
when driving the vehicle through it. Please note
that the water level is correspondingly lower for
flowing water.
!Never accelerate before driving into the
water. The bow wave could force water into the
engine and auxiliary equipment, thus damaging
them.
!Do not open any of the vehicle’s doors while
driving through water. Water could otherwise en-
ter the vehicle interior and damage the vehicle’s
electronics, as well as the interior equipment.
!Obstacles can damage the vehicle
underbody or suspension components. If possi-
ble use the assistance of a second person out-
side the vehicle to scout the path you intend to
take and check for adequate ground clearance
when you cross obstacles with your vehicle. The
person assisting you outside the vehicle should
always be a safe distance away from the vehicle
and positioned so that he or she cannot get hurt
in case of any unexpected vehicle movement.
After off-road driving or crossing obstacles, in-
spect vehicle for any damage, especially vehicle
underbody and suspension components. Failure
to do so can adversely affect the vehicle’s future
performance, including increased chance of an
accident.

326 Operation
Driving instructions
When driving over tree stumps, big rocks
and other obstacles, observe the following
rules:

Make sure the off-road driving program
(
page 253) is switched on.

Avoid high engine speeds.

Shift automatic transmission to
position1 (
page 192).

Check the vehicle clearance before
crossing obstacles.

Cross obstacles (e.g. tree stumps or
big rocks) very slowly by aiming one of
the front wheels at the center of the ob-
stacle, and repeat same with the rear
wheel.Driving on sand
When driving on sand, observe the follow-
ing rules:

Vehicles with air suspension program*:
Set the raised level (
page 255).

Avoid high engine speeds.

Shift automatic transmission into a
gear range that is appropriate for the
terrain.

In sandy soil, drive at a steady speed as
conditions permit. This helps overcome
the vehicle rolling resistance and re-
duce the likelihood of the vehicle sink-
ing into the ground.

Drive in tracks of other vehicles if they
are not too deep and you have suffi-
cient clearance.
Ruts
A number of off-road tracks or other by-
ways have deep ruts which can cause the
underbody to come in contact with the
ground.

Make sure the off-road driving program
(
page 253) is switched on.

Vehicles with air suspension program*:
Set the raised level (
page 255).
!Special attention is needed when you cross
obstacles on a steep incline.
The vehicle could slide sideways as a result of its
possible slanted position which in turn may
result in the vehicle tipping or rolling over.
Warning!G
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure (
page 359) before continuing
your trip. Driving with reduced tire inflation
pressure increases the risk of losing control
of the vehicle and rolling over.

327 Operation
Driving instructions

Avoid high engine speeds.

Shift automatic transmission to
position1 (
page 192).

Drive next to the ruts rather than
through them if at all possible.

If the ruts are too deep to drive in, drive
with one side of the vehicle on the
grassy center strip if the route permits.Returning from off-road drivingOff-road driving increases strain on the
vehicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:

Switch off the off-road driving program
(
page 253).

Switch off the DSR (page 250).

Vehicles with air suspension program*:
Lower the vehicle back to a level
suitable for road conditions, e.g. High-
way/High-speed level (
page 255).

Clean all exterior lamps and check for
possible damage.

Clean the front and rear license plate.
!Check that the ruts are not too deep and
your vehicle’s clearance is sufficient. Otherwise:

your vehicle may be damaged

the underbody of the vehicle may come in
contact with the ground and you may get
stuck
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the roadway.
Inspect the tires and under the vehicle for
possible damage. If the vehicle or tires ap-
pear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.
Damage to the vehicle may influence driving
comfort and pose the risk of accident to you
and other drivers.

328 Operation
Driving instructions

Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.

Check tires for possible damage.

Inspect vehicle underbody, oil pan,
brake hoses, etc., as well as vehicle un-
derbody for possible damage.

Check for brush or branches caught in
the underbody.

After continued operation in mud,
sand, water or other dirty conditions
clean the brake discs, wheels, brake
pads and check and clean axle joints.

Conduct a brake test.
Trailer towing Trailer hitch*

Only install a trailer hitch receiver ap-
proved for your vehicle.
For information on availability and in-
stallation, contact an authorized
Mercedes-Benz Light Truck Center.

The bumpers on your vehicle are not
designed for use with clamp-type hitch-
es.
Do not attach rental hitches or other
bumper-type hitches to them.

To reduce the possibility of damage, re-
move the hitch ball adaptor from the
receiver when not in use.
!Brush or branches could increase the possi-
bility of a fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the axles or
drive shafts.
Warning!G
Failure to use proper equipment and driving
technique can result in a loss of vehicle con-
trol when towing a trailer.
Improper towing or failure to follow the in-
structions in this manual can result in vehi-
cle damage and/or serious personal injury.
Follow the guidelines below carefully to as-
sure safe trailer operation.
Contact an authorized Mercedes-Benz Light
Truck Center should you require an explana-
tion of information contained in this manual.

331 Operation
Driving instructions
Make sure the automatic transmission
is set toP (
page 185).
Set the parking brake for the vehicle
(
page 65).
Start the engine (page 54).
Vehicles with air suspension program*:
Set the vehicle level to Highway
(
page 255).
Vehicles with air suspension program*:
Set the ADS* to AUTO or COMFORT
(
page 255).
Turn off the engine (page 66).
Close all doors and the tailgate.
Attach the trailer.
Plug in all electrical connectors.Towing a trailer
There are many different laws, including
speed limit restrictions, having to do with
trailer towing. Make sure your rig will be le-
gal, not only for where you reside, but also
for where you will be driving. A good
source for this information can be the po-
lice or local authorities.
Note the following points, when driving
with the trailer:

In order to gain skill and an understand-
ing of the vehicle’s behavior, you
should practice turning, stopping and
backing up in an area which is free from
traffic.

Before you start driving check the

trailer hitch

break-away switch

safety chains

electrical connections

lighting and tires
!Do not connect a trailer brake system (if
trailer is so equipped) directly to the vehicle’s
hydraulic brake system, as your vehicle is
equipped with antilock brakes. If you do, neither
the vehicle’s brakes nor the trailer’s brakes will
function properly.
iThe provided vehicle electrical wiring
harness for trailer towing has a brake signal wire
for hook-up to a brake controller.
You should consider using a trailer sway control
system. For further information, contact an
authorized Mercedes-Benz Light Truck Center.
iVehicles with air suspension program*:
When you are towing a trailer, the vehicle level
always remains in the Highway setting.
The following applies additionally when towing a
trailer:

The vehicle is lowered to the highway level
when it reaches a speed of 5 mph (8 km/h)
if not set to highway level.

The high-speed level is not available.
The restrictions that apply to towing also apply
when using accessories that are connected to
the trailer power socket, such as a bicycle rack.

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.

343 Operation
Engine compartment
Closing
Let the hood drop from a height of
approximately 1 ft (30 cm).
The hood will lock audibly.
Check to make sure the hood is fully
closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Increased oil consumption
can occur when

the vehicle is new

the vehicle is driven frequently at
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.Checking engine oil level
When checking the oil level

the vehicle must be parked on level
ground

the vehicle must have been stationary
for at least 5 minutes with the engine
turned off
Example illustration ML 350 (ML 320 CDI,
ML 550, ML 63 AMG similar)
1Oil dipstick
2Upper mark
3Lower mark
Warning!G
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure that the hood is securely en-
gaged before driving off. Do not continue
driving if the hood can no longer engage af-
ter an accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.
!Do not use any special lubricant additives,
as these may damage the drive assemblies.
Using special additives not approved by
Mercedes-Benz may cause damage not covered
by the Mercedes-Benz Limited Warranty.
More information on this subject is available at
any Mercedes-Benz Light Truck Center.