FORD 2009 F-550 v.3 - Manual (Page 298)

The 4WD system:
• provides 4x4 High engagement and disengagement while the vehicle is
moving.
• is operated by a rotary control located on the instrument panel that
allows you select 2WD, 4x4 High or 4x4 Low operation.
• uses auto-manual hub locks that can be engaged and disengaged
automatically based on the 4x4 mode selected.
• auto-manual hub locks can be
manually overridden by rotating
the hub lock control from AUTO
to LOCK if desired.
• automatic operation of the
hub locks is recommended, and
will increase fuel economy
• For proper operation, make
sure that each hub is fully
engaged and that both hub
locks are set to the same position (both set to LOCK or both
set to AUTO). To engage LOCK, turn the hub locks completely
clockwise; to engage AUTO, turn the hub locks completely
counterclockwise.
4WD system indicator lights
The 4WD system indicator lights illuminate only under the following
conditions. If these lights illuminate when driving in 2WD, contact your
authorized dealer as soon as possible.
• 4x4 HIGH - momentarily
illuminates after the engine is
started. Illuminates when 4H (4x4
High) is engaged. Flashes when
shifting into or out of 4H (4x4 high) (ESOF systems only).
• 4x4 LOW – momentarily
illuminates when the ignition is
turned to the ON position.
Illuminates when 4L (4x4 Low) is
engaged. Flashes when shifting into or out of 4L (4x4 Low) or if the
range shift conditions are not met (ESOF systems only).
4x4
HIGH
4x4
LOW
2009 F-250/350/450/550 (f23)
Owners Guide, 3rd Printing
USA (fus)
Driving
298