Originally Posted by Phil57
Boo are you saying that when you push the mode button the red light does not come on? There is also a program called diagnostics that needs to be turned on to give you transmission fluid information. I'm wondering if that is the confusion. The mode button is only a slight change in the shift points. If I had to guess I would say it drops the shift by 200 rpm. When you are going down the highway at 62 - 63 it will go into 6 gear at a lower RPM with the mode button on meaning the red light is lit. It will change the shift points for all 6 gears. If your red light does not com on you may have a LED burned out. I think a call to Allison may be a good idea. My 2011 390RB 340 chassis was made in Oct 2010 and has mode function but not diagnostics and it would be cost prohibitive to try to add it.
I've read about the diagnostics thing (hold down both arrows at once, I think) to read trans temp, oil levels, etc. But I've not tried it yet.
I have the mode BUTTON but the light never comes on and I also notice no change in the shift points no matter how many times I push it. In my mind 200 RPM difference is quite significant.
I typically drive at about 59 or so (to keep the MPG up) but at that speed I can't get out of 5th. Mine doesn't shift to 6th until around 68 MPH.
Sorry for always mentioning trucks, but in a standard 10 speed (manual) truck tranny each gear is exactly 300 RPM apart; that's why I feel that a 200 RPM change in shift points is quite a lot.