Mercedes-Benz 2005 M-Class Operator's Manual page 256

Practical hints
What to do if ...
Problem
?
(USA only) The yellow engine malfunction
indicator lamp comes on while
±
(Canada only)
driving.
254
Possible cause
There is a malfunction of:
The fuel management
system
The ignition system
The emission control
system
Systems which affect
emissions
Such malfunctions may result
in excessive emissions values
and may switch the engine to
its limp-home (emergency op-
eration) mode.
Suggested solution
Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics sys-
tem. It allows the accurate identifica-
tion of system malfunctions through
the readout of diagnostic trouble
codes. It is located in the front left area
of the footwell next to the parking
brake pedal.