For a while now my truck has been shifting hard, and w/4 times having the taps being cleared it will not shift right. So allison says they can put in a new shift program, so we hook up the laptop computer and go driving, What this tech finds is. T.P.S. Is falling off the chart and so is voltage and turbin speed, no codes are set, he thinks its a conection problem or T.C.M.problem, also it would show nuetral for a spilt second also may think my NSBU switch is bad, could this effect the shifting? and can the voltage,tps and tubin speed droping be the case of my hard shifting??? Anybody ever have this problem. And another thing, my silpage on my monitor is showing 1-2% and 0% to but it use to show 0% all the time This is in 5th lockup, but when i had the allison tech do a slip test in all the gears it showed 0% slip on all,even in 5th, so im thinking do i have a bad connection in my dats bus, or what ever they call it were the chips hook up. Again thanks for any help

Thanks
Cody.

definately sounds like you have some nsbu issues, get that fixed then go from there.

WOW!!!

It works now, why i was @ allison they did clear the taps w/the allison program and DIDNOT put it fast learn, they say its better to have it adapt on its own.Well it worked and i have defuel on all shifts no harsh or hard shifts. Im a happy person now!!!!):h ):h Since its been almost a year that this tranny has done this.
Cody.

Mine did the same thing. I took it to the local stealership (right after i bought it used) expecting the worst. I was not too familiar with the D/A combo. They hooked it up to a computer and reprogrammed it in like 5 minutes and did not charge me even though the truck is out of warrenty.