03 TB transmission alternates between 3-4 at 2 per second when slowly placed under load grade 45 to 55mph also engine changes 200 every 15-20 seconds AC on or off Cruise on or off no difference?

Had the same issue. The dealer reprogrammed the computer and it went away. I believe it was the power management that was a problem because I had an annoying part throttle hesitation that was also fixed by the reprogram.This is a common problem with the 4L60E/700R4. Reprogram or shift kit will eliminate, as well as driving in 3rd at speeds below 45-50mph. Less wear on the clutch packs.