Ford 2006 Expedition Owner's Manual page 583

How to use the automatic locking mode
1. Buckle the combination lap and
shoulder belt.
2. Grasp the shoulder portion and
pull downward until the entire belt
is pulled out.
3. Allow the belt to retract. As the belt retracts, you will hear a clicking
sound. This indicates the safety belt is now in the automatic locking
mode.
How to disengage the automatic locking mode
Unbuckle the combination lap and shoulder belt and allow it to retract
completely to disengage the automatic locking mode and return to the
vehicle sensitive (emergency) locking mode.
After any vehicle collision, the combination lap and shoulder belt
system at all passenger seating positions must be checked by an
authorized dealer to verify that the "automatic locking retractor"
feature for child seats is still functioning properly, in addition to other
checks for proper safety belt system function.
2006 Expedition (exd)
Owners Guide (post-2002-fmt)
USA (fus)
Seating and Safety Restraints
175