Ford F-150 Owner's Manual page 163

For 4WD vehicles
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Pull the 4WD control knob toward you.
For 2WD vehicles
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Turn the control to ON.
Once the indicator light
illuminates in the information
display, both rear wheel axle
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shafts will be locked together providing
added traction.
If the indicator does not come on, or the
indicator turns off while driving, one of the
following has occurred:
F150 (TF6) , enUSA
Rear Axle
• The vehicle speed is too high.
• The left and right rear wheel speed
difference is too high during an
engagement attempt.
• The system has malfunctioned and is
accompanied by CHECK LOCKING
DIFFERENTIAL in the information
display. See your authorized Ford
dealer for assistance.
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