Overdrive is kicking in to soon
it can, in fact newer cars do it even more.. .saves fuel....
if fact new cars have fast 1 to 4 gear jump, (no load) MPG feature.
what is it doing and when, and under what loads?????
do you mean downshifting too soon?
OD is top gear. and TCC is torque converter lockup
down shifting happens 3 ways
1: you do it. shifter.
2: low vacuum this is the Load sense, hills cause low vacuum and it down shifts.
3: TV, this is throttle valve , sensed, you stab throttle to pass.
aka; detent, TV. passing gear.
on some cars there is an OD switch to cut out OD, say pulling trailer
pulling any heavy load, may case the OD to hunt, or the TCC to hunt
and is a real pain....
btw the FSM covers all 100 A/T issues, up shifts, down, slips. flare, early ,late. ... its complex device, tend to not own them.