Ford 1997 Aerostar Manual page 178

How the Electronic 4-Wheel Drive (E-4WD)
System Works
Under normal driving conditions, when the road
is firm, dry and level, the engine power is
distributed one-third to the front axle and
two-thirds to the rear axle. However, if a wheel
begins to slip, the microprocessor will sense this
condition and signal the system to transmit more
power to the axle with more traction. (You may
feel a momentary surge of power.)
NOTE: The microprocessor is disabled when
the brakes are applied or when the
transmission selector is in the P (Park)
or N (Neutral) positions.
Driving Your Electronic 4-Wheel Drive
(E-4WD) Vehicle
Since your E-4WD vehicle is unique, follow these
steps to be safe:
Avoid unnecessary turns or other maneuvers
that could cause loss of control and possible
injury.
Use the same size and type of tire and wheel
as originally provided for your vehicle and
inflate the tires to the manufacturer's
recommended air pressure.
Become familiar with your vehicle's operating
characteristics and study this Owner Guide
for specific operating instructions. Be sure all
occupants wear the safety belts provided.
Drive cautiously, defensively, and at speeds
safe for current road conditions.
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