Porsche 928 S 1984 Owner's Manual page 23

Safety belt warning system
An audio-visual warning system is inter-
connected with the driver's safety belt.
Every time the ignition is turned on, the seat
belts warning light will come on for about 6
seconds as a reminder to buckle up. If the dri-
ver does not fasten the safety belt, the gong
will also come on for the duration of this six
second period. The gong will go off as soon as
the driver has buckled up.
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