Tow/haul mode

[JE_6.4]

Having issues with tow haul.

Seems that it will only switch to tow when the truck is in park or neutral, not in drive or reverse.
Read it could be the common wiring issue but I checked continuity and it's not that. I didn't suspect it would be as it is religious about it being in park or neutral.
Only started doing it after a new trans tune. Trans was taking forever to learn daily driving so went ahead and did the ford relearn procedure. That was the last time it would switch tow/haul on and off on the fly.
Any ideas?

 

[6.0 Tech]

Sounds like a tuning issue if it was working fine before hand.

 

[JE_6.4]

I should have explained better. It was working as it should until yesterday. Then when I tried again it would not work. Guess I'll reload the tunes and see if it makes a difference.