Well you can assume manual control in a sense but not like Ken who has bypassed the 'puter. Here's what I do. As soon as my temp hits 128 my OD will kick in. I watch for this and turn off the OD using the Shifter switch. I then drive and shift normal and turn the OD back on when I need to lower the rpms. When I 'shift' into OD I always depress the clutch just like a normal shift. Saves the 'thump' when it kicks in automatically. I also use it to downshift when in OD and 4th. I depress the clutch, turn the OD off and let out. It's like I downshifted, which of course I just did. So I am 'manually controlling' the OD by not letting the computer do it. A benefit of still having the 'puter is if I do have to 'jump on it' in a hurry, the 'puter will downshift out of OD for me.