Ford F-150 2000 Introduction Manual page 96

Controls and features
Locking the doors with the keyless entry system
It is not necessary to enter the factory or personal code prior to locking
all doors. To lock the doors:
Press the 7/8 control and the 9/0 control at the same time.
Activating/deactivating autolock with the keyless entry system
Before following the activation or deactivation procedures, make sure
that the anti-theft system (if equipped) is not armed, ignition is off, and
all vehicle doors and liftgate window are closed.
1. Enter 5 digit entry code
2. Press and hold 7/8 control
3. Press and release 3/4 control while holding 7/8 control
4. Release 7/8 control.
The horn will chirp once if autolock was deactivated or twice (one short
and one long chirp) if autolock was activated.
To re-activate autolock, repeat steps 1–4.
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