2007 MERCEDES-BENZ ML320CDI check engine

418 Practical hintsWhat to do if …Problem
Possible cause/conse-
quence
Suggested solution
?
(USA only)
±
(Canada only)
The yellow engine malfunction
indicator lamp comes on while
driving.
A loss of pressure has been
detected in the fuel system.
The fuel cap may not be closed
properly.
The fuel system may be leaky.

Check the fuel cap (
page 352).
If it is not closed properly:

Close the fuel cap.
If it is closed properly:

Have the fuel system checked by an
authorized Mercedes-Benz Light Truck
Center.
Your fuel tank is empty.

After refueling start, turn off and
restart the engine three or four times in
succession.
The limp-home mode is canceled. You do
not need to have your vehicle checked.

446 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display messages
Possible cause/consequence
Possible solution
#
The battery is no longer charging.
Possible causes:

alternator malfunctioning


broken poly-V-belt
Do not forget that the brake system
requires electrical energy and may be
operating with restricted capability.
Considerably greater brake pedal
force is required and the stopping dis-
tance is increased.

Stop the vehicle in a safe location or as
soon as it is safe to do so.

Apply the parking brake (
page 65).

Check the poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Notify an authorized
Mercedes-Benz Light Truck Center.
If it is intact:

Drive immediately to the nearest
authorized Mercedes-Benz Light Truck
Center. Adjust driving to be consistent
with reduced braking responsiveness.

449 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
;
(USA only)
3
(Canada only)
Check
brake fluid level
There is insufficient brake fluid
in the reservoir.

Risk of accident! Stop the vehicle in a
safe location or as soon at is safe to do
so.

Apply the parking brake (
page 65).

Notify an authorized Mercedes-Benz
Light Truck Center. Do not add brake
fluid! This will not solve the problem.
?
(USA only)
±
(Canada only)
Engine
Service
There may be a malfunction in
the

fuel injection system


ignition system


exhaust system


fuel system

Have the engine checked by an
authorized Mercedes-Benz Light Truck
Center.
Warning!
G
Driving with the message
Check brake
fluid level
displayed can result in an ac-
cident. Have your brake system checked im-
mediately. Do not add brake fluid before
checking the brake system. Overfilling the
brake fluid reservoir can result in spilling
brake fluid on hot engine parts and the
brake fluid catching fire. You could be seri-
ously burned.
!
If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks.

450 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
Ï
Coolant level
Stop car, switch engine off
The coolant is too hot.
Among other possible causes
(the cooling fan could be
malfunctioning), the poly-V-belt
could be broken.

Stop the vehicle in safe location or as
soon as it safe to do so.

Apply the parking brake (
page 65).

Turn off the engine.

Check the poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise, the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Contact an authorized
Mercedes-Benz Light Truck Center.
If it is intact:

Do not continue to drive the vehicle with
this message displayed. Doing so could
result in serious engine damage that is
not covered by the Mercedes-Benz Limit-
ed Warranty.
(Continued on next page)

452 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
B
Top up Coolant
See Oper. Manual
The coolant level is too low.

Add coolant (
page 362).

If you have to add coolant frequently,
have the cooling system checked by an
authorized Mercedes-Benz Light Truck
Center.
Warning!
G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.Warning!
G
In order to avoid potentially 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 coolant temperature is
above 158°F (70°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
1/2 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.
!
Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant
in the cooling system. The engine will overheat
causing major engine damage.

453 Practical hints
What to do if …
When the message
Add 1 qt. engine oil
at next refueling (Canada:
1 liter
)
appears while the engine is running and at
operating temperature, the engine oil level
has dropped to approximately the mini-
mum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest
service station where the engine oil should
be topped to the required level with an ap-
proved oil specified in the Factory
Approved Service Products pamphlet.
Display symbol
Display messages
Possible cause/consequence
Possible solution
N
Check eng. oil level
at next refueling
The engine oil level is too low.

Check the engine oil level (
page 360)
(except ML 500), or (
page 358)
(ML 500 only).
USA only:Add 1 qt. engine oil
at next refuelingCanada only:Add 1 liter engine oil
at next refueling
The engine oil level is too low.

Add engine oil (
page 361) and check
the engine oil level (page 360) (except
ML 500), or (
page 358) (ML 500 only).
Engine oil level
cannot be measured
The measuring system is
malfunctioning.

Have the measuring system checked by
an authorized Mercedes-Benz Light Truck
Center.

454 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/conse-
quence
Possible solution
N
Engine oil level
Stop car, turn engine off
There is no oil in the engine.
There is a danger of engine
damage.

Carefully bring the vehicle to a halt as soon as
it is safe to do so in a safe location.

Turn off the engine.

Add engine oil (
page 361) and check the en-
gine oil level (
page 360) (except ML 500), or
(
page 358) (ML 500 only).
Engine oil level
Reduce oil level
You have added too much
engine oil. There is a risk of
damaging the engine and/or
the catalytic converter (gaso-
line engine) or the oxidation
catalyst (diesel engine).

Have oil siphoned or drained off.
Observe all legal requirements with respect to
its disposal.
Engine oil level
Visit workshop
The engine oil has dropped to
a critical level.

Check the engine oil level (
page 360) (except
ML 500), or (
page 358) (ML 500 only) and
add oil as required (
page 361).

If you must add engine oil frequently, have the
engine checked for possible leaks.
!
The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damagethat is not covered by the Mercedes-Benz
Limited Warranty.

508 Practical hintsBattery!
The battery is a valve-regulated lead acid
(VRLA) battery, also referred to as “fleece” bat-
tery. Such batteries do not require topping-up of
the electrolyte level. VRLA batteries therefore do
not have cell caps and the battery cover is
non-removable. Do not attempt to open the bat-
tery as otherwise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, the battery may dis-
charge if the vehicle is not operated for an ex-
tended period of time. You can connect a battery
maintenance charge unit tested and approved
for use on your vehicle model or disconnect the
battery to prevent battery discharge. Contact an
authorized Mercedes-Benz Light Truck Center
for more information.
!
The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation hose
(
page 513) and the lateral plug (
page 513)
must always be securely installed when the
vehicle is in operation.
Warning!
G
Jump starting must only be done using the
jump-start contacts located in the engine
compartment (
page 515).
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 507).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.