[CaptainGizmo]

I've spent WAY WAY WAY too many hours, phone calls, and head-banging on this topic to even try to remember!
When I had our Dutch Star, I discovered an issue with programming, only after getting "reprimanded" by so many who said I was not using the CC correctly.
I've been in California my whole life, and have driven so many mountain roads in the western states; 70 down from Breckenridge is a nice steep one, along with our constant playground through the Sierras, the Gravepine, and Devore pass. These all range from 6 to 9% on average, so I feel I've had a lot a "Jake" experience.

Ok, all that background said, I have a Cummins/Allison so mine's not the same programming, but the principles of the way they've been programmed still apply.

There are special settings in the computer that control how much "over" or "under" the set point, the CC will allow the rig to go before "doing something". Something CAN mean, accelerate/deaccelerate, Jake ON/OFF AND WHAT STAGE!! That's what the gotcha is!!

Cummins had to use a compter to find out that my Dutch Star wasn't activating the HIGH stage when in CC! This can really affect decceleration and Jake performance and is why lots of folks choose just to turn it off in the hills.

On our Newell, I really can't tolerate having the CC on going down grades much at all. Reason being, it holds the Jake off too long, and causes my speed to over-run way too much for my defensive feel.

I hope all this helps you. I really doubt you'll have to manually downshift your CAT, so long as you disengage your CC. But, my guess is, if you DO leave the CC engaged, you're not going to like it.