FORD 2013 Flex v.1 - Manual (Page 216)

USING YOUR ALL-WHEEL DRIVE (AWD) SYSTEM (IF EQUIPPED)
AWD uses all four wheels to power the vehicle. This increases traction,
enabling you to drive over terrain and road conditions that a
conventional two-wheel drive vehicles cannot. The AWD system is active
all the time and requires no input from the operator.
Note: Your AWD vehicle is not intended for off-road use. The AWD
feature gives your vehicle some limited off-road capabilities in which
driving surfaces are relatively level, obstruction-free and otherwise
similar to normal on-road driving conditions. Operating your vehicle
under other than those conditions could subject the vehicle to excessive
stress which might result in damage which is not covered under your
warranty.
Note: When an AWD system fault is present, the warning Check AWD
will display in the message center. The AWD system is not functioning
correctly and defaulted to front-wheel drive. When this warning is
displayed, have your vehicle serviced at an authorized dealer.
Note: The AWD Off message may also be displayed in the message
center if the AWD system has overheated and defaulted to front-wheel
drive. This condition may occur if the vehicle was operated in extreme
conditions with excessive wheel slip, such as deep sand. To resume
normal AWD function as soon as possible, stop the vehicle in a safe
location and stop the engine for at least 10 minutes. After the engine has
been restarted and the AWD system has adequately cooled, the AWD Off
message will turn off and normal AWD function will return. The AWD Off
message will turn off when the system cools and normal AWD function
returns.
If your vehicle is equipped with AWD, a spare tire of a different size
other than the tire provided should never be used. If the mini-spare tire
is installed, the AWD system may disable automatically and enter
front-wheel drive only mode to protect driveline components. This
condition may be indicated by an AWD Off message in the information
display. If there is an AWD Off message in the message center from using
the spare tire, this indicator should turn off after reinstalling the repaired
or replaced normal road tire and cycling the ignition off and on. It is
recommended to reinstall the repaired or replaced road tire as soon as
possible. Major dissimilar tire sizes between the front and rear axles
could cause the AWD system to stop functioning and default to
front-wheel drive or damage the AWD system.
216 All-Wheel Drive
2013 Flex (471)
Owners Guide gf, 1st Printing
USA (fus)