2006 MERCEDES-BENZ ML500 engine overheat

407 Practical hints
What to do if …
Symbol messagesDisplay symbol
Display messages
Possible cause
Possible solution
#
Undervoltage
Switch off consumers
The battery has insufficient volt-
age.

Turn off unnecessary electrical
consumers.
malfunction
Visit workshop
The battery was charged with a
battery charger or jump started.

Have the battery checked at a service
station.
Battery/Alternator
Stop vehicle
The battery is no longer charg-
ing.
Possible causes:

alternator malfunctioning


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

Stop immediately and 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 autho-
rized Mercedes-Benz Light Truck Center.
Adjust driving to be consistent with re-
duced braking responsiveness.

410 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
?
(USA only)
±
(Canada only)
Visit workshop
There may be a malfunction in
the:

Fuel injection system


Ignition system


Exhaust system


Fuel system

Have the measuring system checked by
an authorized Mercedes-Benz Light Truck
Center.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 332).

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 can be seriously burned.
!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 en-
gine damage.

411 Practical hints
What to do if …
During severe operation conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.

Stop the vehicle and immediately turn off
the engine.

Only start the engine again after the mes-
sage disappears. You could otherwise
damage the engine.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
damage which is not covered by the
Mercedes-Benz Limited Warranty.

412 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The poly-V-belt could be broken.

Stop the vehicle and immediately 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. Notify 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.

Drive immediately to the nearest autho-
rized Mercedes-Benz Light Truck Center.
Coolant
Visit workshop
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature gauge
in the instrument cluster.

Have the fan replaced as soon as possi-
ble.