Mercedes-Benz 2008 M-Class Operator's Manual page 408

Problem
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During driving the red seat belt
telltale flashes and you addition-
ally hear an intermittent warning
chime with increasing intensity.
i
After 60 seconds with an unfastened seat
belt on one of the front seats, the warning chime
stops sounding and the seat belt telltale
illuminates continuously. The seat belt telltale
will only go out if both, the driver and front
passenger's seat belt are fastened, or the vehi-
cle is standing still and a front door is opened.
Possible cause/consequence
The vehicle's speed once exceeded 15 mph
(25 km/h) and you and/or your front pas-
senger have forgotten to fasten your seat
belts.
There are items placed on the front passen-
ger seat and therefore the system senses the
front passenger seat as being occupied.
Practical hints
What to do if ...
Suggested solution
Fasten your seat belts.
The seat belt telltale goes out and the
warning chime stops sounding.
Remove the items from the front pas-
senger seat and put them in a safe
place.
The seat belt telltale goes out and the
warning chime stops sounding.
407