I have a 2010 Enclave - trying to get a brake controller to work. Did you install your own or have it done?
Also, I assumed the Tow mode would lock out overdrive. I towed my trailer empty (not using brakes) and it seemed to avoid overdrive. Worked well, just wish I could get the controller working so I can tow what I bought the trailer for!
What do you mean when saying "trying to get a brake controller to work"?
I installed my own and it was easy. I did buy a plug and play cable but could of used the one that came with the vehicle.
Which brake controller do you have?
No brake controller in my case because it's a surge brake trailer. Mine was definitely shifting into 6th even with tow haul mode enabled. I'm going to give it another shot in a couple months when the boat comes out of storage though because from what I've read as long as I stay 65 or under tow/haul should be locking out 6th gear.
It is rare
that the vehicle will shift into 6th when driving below 65 - but since I drive a 55mph 98% of the time I can say that it is POSSIBLE for it to
go to 6th gear with the tow/haul switch on. Again rare but it can happen. So your statement is basically correct - at a lower speed, it is in 5th most of the time,
with the tow switch on.
For that reason I tow 90% of the time with the tow switch OFF - that way on flat and level most of the time
it will go into 6th gear when I tow at 55mph. Just so you know.