Mercury Mountaineer 2009 Owner's Manual page 706

Driving
Driving with a 5–speed automatic transmission (if equipped)
This vehicle is equipped with an Adaptive Transmission Control Strategy.
This Adaptive Transmission Control Strategy offers the optimal
transmission operation and shift quality. When the vehicle's battery has
been disconnected for any type of service or repair, the transmission will
need to relearn the normal shift strategy parameters, much like having to
reset your radio stations when your vehicle battery has been
disconnected. The Adaptive Transmission Control Strategy allows the
transmission to relearn these operating parameters. This learning process
could take several transmission upshifts and downshifts; during this
learning process, slightly firmer shifts may occur. After this learning
process, normal shift feel and shift scheduling will resume.
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2009 Mountaineer (mnt)
Owners Guide, 1st Printing
USA (fus)