Could is be "stuck" in Tow/Haul Mode? The the 70@16-1800 is about right. Mine will hang out at the 22-2400@70 in T/HM when towing, but will eventually settle in to 6th and drop back to 16-1800....... If you push the button, does the Tow/Haul light come on? I agree, it needs to be scanned, just because there is no CEL, doesn't mean there isn't a code......
To clarify my 6th comment.....
The 5R110 actually has 6 gears. when the transmission is cold what should be the 4th to 5th shift (next to last, and highest gear) is not a smooth as the engineers would have liked. So to correct the issue, there was a 6th ratio added to the transmission, so 4th gear and 5th gear are ALMOST the same ratio, but not exactly. So a 5R110 when cold, actually shifts: 1,2,3,4,6 and once it warms up it is 1,2,3,5,6 so most of the time it is the second pattern.