2003 MERCEDES-BENZ ML320 check engine

191 Operation
Driving instructions
Returning from off-road drivingOff-road driving increases strain on the ve-
hicle.
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 LOW RANGE mode
(page 118).


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.


Inspect frame, oil pan, brake hoses,
etc., as well as vehicle underbody for
possible damage.


Check tires for possible damage, clean
all exterior lamps, and conduct a brake
test.


Check for brush or branches caught in
the undercarriage.
They could increase the possibility of a
fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the
axles or drive shafts.


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

195 Operation
Driving instructions
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.


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


When towing a trailer, check occasion-
ally to be sure that 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.
I t i s m o r e p r o n e t o r e a c t i n g t o s i d e w i n d
gusts, and requires more sensitive
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 hunts between
gears on inclines, manually shift to a
lower gear (select 4, 3, 2 or 1).
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 selector lever in position1, switch
transfer case to LOW RANGE mode
(page 118).


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 trailer should begin to sway, re-
duce 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 trail-
er by increasing the speed or over-
steering and stepping on the brakes.

201 Operation
At the gas station
Check regularly and before a long trip
Open the hood (
page 202)
1Engine oil level
More information on engine oil can be
found in the “Operation” section
(
page 203).
2Coolant level
For normal replenishing, use water (po-
table water quality). More information
on the coolant level can be found in the
“Operation” section (
page 206).
3Brake fluid
More information on brake fluid can be
found in the “Technical data” section
(
page 284).4Windshield washer and headlamp
cleaning system
More information on filling the reser-
voir can be found in the “Operation”
section (
page 208).
Vehicle lighting
Check function and cleanliness. More in-
formation on replacing light bulbs can be
found in the “Practical hints” section
(
page 247).
Combination switch (
page 102).
Tire inflation pressure
More information on tire inflation pressure
can be found in the “Operation” section
(
page 211).
iLeaving the engine running and the fuel
cap open can cause the
?
lamp to
illuminate.
See also “Practical hints” section
(
page 232).

203 Operation
Engine compartment
Closing
Let the hood drop from a height of ap-
proximately 1ft (30cm).
The hood will lock audibly.

Check to make sure that 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. Higher oil consumption can
occur when

the vehicle is new


the vehicle is driven frequently at high-
er 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


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from vehicle and do not open the hood
until the engine has cooled. If necessary,
call the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition coils, spark plug sockets, diagnostic
socket) of the ignition system

with the engine running


while starting the engine


if ignition is “on” and the engine is
turned manually
Warning!
G
Be careful that you do not close the hood on
anyone.!Do not push the hood closed manually,
as this could damage it.

204 OperationEngine compartmentEngine oil level display
1Knob
2Display in speedometer
Switch on the ignition and wait until the
display
- - - - - -
appears in the
speedometer display2.

Within one second press knob1 twice.
One of the following messages will subse-
quently appear in the display:


OIL i.OThe oil level is correct. Engine oil does
not to be added.


– 1.0 L
Add 1 liter of engine oil.


– 1.5 L
Add 1.5 liters of engine oil.


– 2.0 L
Add 2 liters of engine oil.


OIL HIThe oil level is too high.
Have excess oil siphoned.The display
- - - - - -
flashes in the
speedometer display if a proper oil level
check cannot be performed.

Repeat the engine oil level check after
a few minutes.
!Excessive oil must be siphoned or
drained off. It could cause damage to
the engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
iIf the engine oil level check cannot be
performed again via the display field,
use the dipstick to perform the engine
oil level check (
page 205).
In this case we recommend that you
have the system checked at a
Mercedes-Benz Light Truck Center.

206 OperationEngine compartmentTransmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Light
Truck Center check the automatic trans-
mission.Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool. 1Cap
2COLD LEVEL mark
The coolant level should reach the COLD
LEVEL mark2 in the reservoir.

Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.
Warning!
G
In order to avoid any possibly serious burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.


Do not remove pressure cap on coolant
reservoir if engine temperature is above
194°F (90°C). Allow engine to cool
down before removing cap. The coolant
reservoir contains hot fluid and is under
pressure.


Using a rag, slowly open the cap approx-
imately ½ turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.
iIf the engine is already at its regular op-
erating temperature, the coolant may
be approximately 0.6 in (1.5 cm) above
the COLD LEVEL mark.


207 Operation
Engine compartment

Continue turning the cap to the left and
remove it.

Add coolant as required.

Replace and tighten cap.
More information on coolant can be found
in the “Technical data” section
(
page 287).
Battery
The battery is located in the engine com-
partment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle mostly for short dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing batteries, always use bat-
teries approved by Mercedes-Benz.If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Light Truck
Center about steps you need to observe.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.

213 Operation
Winter driving
Winter driving
Before the onset of winter, have your vehi-
cle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing temperatures
(page 290).


Battery test. 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.


Tire change. We recommend M+S rat-
ed radial-ply tires on all four wheels for
the winter season.
Winter tires
Always use winter tires at temperatures
below 39°F (4°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS, ESP, 4-ETS and
EBP in winter operation.
For safe handling, ensure that all winter
tires mounted are of the same make and
have the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available from your tire dealer or
from any authorized Mercedes-Benz Light
Truck Center.Warning!
G
Winter tires with a tread depth under 0.16 in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.