FORD 2006 Explorer v.1 - Manual (Page 218)

If the parking brake is fully released, but the brake warning lamp
remains illuminated, the brakes may not be working properly.
See your authorized dealer.
Driving with a 5–speed automatic transmission
This vehicle is equipped with an adaptive Transmission Shift Strategy.
Adaptive Shift 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 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.
Driving
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