Mazda mazda3 2015 Owner's Manual page 263

When Driving
i-ACTIVSENSE
NOTE
If the LDWS warning sound is set to
rumble, the sound will be heard from
the vehicle speaker on the side which
the system determined the vehicle
may be deviating from its lane.
The LDWS warning sound may
not be heard depending on the
surrounding conditions such as
outside noise.
The warning timing with which the
system determines the vehicle may
be deviating from its lane can be
changed.
Refer to Personalisation Features on
page 9-16 .
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