Transmission Puzzle

[Mr Campbell]

2004 Bonneville SLE, 107k miles.
step on gas, at 65 mph it acts like a govener/limiter.
Cruise at 70 mph, slight hill, some times it kicks out, rpm goes up to 5k. hit brake, slightly press peddel car will increase in speed or use cruise accel.
step on it after 65 mph and acts like a govenor.
at 65 plus, floor it and hold it down, kicks out for 2 sec, then kicks in for half sec then back out for 2 sec.
Know ones knows what this is about. please helpl.