Ford F-150 Owner's Manual page 327

Activating the electronic locking differential (ELD)
The ELD can be turned on by
pulling the 4WD control knob
toward you (4x4 vehicles) or by
turning the ELD control knob from
OFF to ON (4x2 vehicles).
Once the indicator light is displayed
in the message center, both rear
wheel axle 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:
• 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 will be accompanied by a CHECK
LOCKING DIFFERENTIAL message in the message center.
Note: If the ELD has difficulty disengaging, release the accelerator pedal
and turn the steering wheel in the opposite direction while rolling.
Basic operating principles
Do not use 4WD on dry, hard surfaced roads. Doing so will produce
excessive noise and vibration and increase tire wear. 4WD modes are
only intended for consistently slippery or loose surfaces.
Parking
On 4WD vehicles, when the transfer case is in the N (Neutral) position
for recreational towing purposes, the engine and transmission are
disconnected from the rest of the driveline. Therefore, the vehicle is free
to roll even if the automatic transmission is in P (Park) or the manual
transmission is in gear. Do not leave the vehicle unattended with the
transfer case in the N (Neutral) position. Always set the parking brake
fully and turn off the ignition when leaving the vehicle. Refer to
Recreational towing for more information.
2012 F-150 (f12)
Owners Guide, 2nd Printing
USA (fus)
Driving
327