My two cents....

Shift into 4 low and see if the front wheel indicators in the TOD icon light up.

Did you change the powertrain control module? It's the box located at the bottom of the center console, in front of the gear selector, under the rounded black cover.

Try operation in the individual gear selections (1,2,3,D,R). Does the problem occur in all gears?

There are about a dozen connectors associated with the TOD circuits, located all over the truck. Any one of them could be a problem.

Download the repair CD off of Tone's site, www.tonemonday.com. It's under the VehiCROSS section and it's FREE.