Ford Explorer 2009 Owner's Manual page 200

Seating and Safety Restraints
The Belt-Minder feature uses information from the front passenger
sensing system to determine if a front seat passenger is present and
therefore potentially in need of a warning. To avoid activating the
Belt-Minder feature for objects placed in the front passenger seat,
warnings will only be given to large front seat occupants as determined
by the front passenger sensing system.
Both the driver's and passenger's safety belt usages are monitored and
either may activate the Belt-Minder feature. The warnings are the same
for the driver and the front passenger. If the Belt-Minder warnings have
expired (warnings for approximately five minutes) for one occupant
(driver or front passenger), the other occupant can still activate the
Belt-Minder feature.
When the Belt-Minder feature is activated, the safety belt warning light
illuminates and the warning chime sounds for six seconds every
30 seconds, repeating for approximately five minutes or until the safety
belts are buckled.
The Belt-Minder feature uses two different warning chimes. During the
first minute of activation, the warning chime will sound once every
second. The remaining warning chimes will sound twice every second
while the system is activated.
If...
The driver's and front
passenger's safety belts are
buckled before the ignition
switch is turned to the on
position or less than
1-2 minutes have elapsed since
the ignition switch has been
turned on...
The driver's or front
passenger's safety belt is not
buckled when the vehicle has
reached at least 3 mph
(5 km/h) and 1-2 minutes have
elapsed since the ignition
switch has been turned to on...
200
Then...
The Belt-Minder feature will not
activate.
The Belt-Minder feature is activated
- the safety belt warning light
illuminates and the warning chime
sounds for six seconds every
30 seconds, repeating for
approximately five minutes or until
the safety belts are buckled.