Mercedes-Benz 2008 M-Class Operator's Manual page 428

Symbol messages
Display symbol Display message
ò
Replace air filter.
#
Possible cause/consequence
The air filter is clogged.
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.
Possible solution
Have the air filter checked by an authorized
Mercedes-Benz Light Truck Center.
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.
Contact 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.
Practical hints
What to do if ...
427