I’ve been running my SCT Strategy Flash programmer on my 2001 Ford F250 with no problems for approximately 5 months now and have been completely satisfied until a couple of days ago.
I decided to change the program from the “tow” setting to the “street” setting. The program loaded with no problems but once I started driving, every shift felt like the truck was de-fueling, or cutting out, for half a second (that’s the best way I can think of to describe it). It’s like the engine cuts out for a second and throws you forward in the seat, but then immediately kicks back in and sets you back again.
I’ve tried changing the tune several times now, back to the “tow” setting, over to the “performance” setting, and over again to the “street” setting. The shifting problem persists. I returned the truck to stock and the truck shifted normally again with no cut-outs between shifts.
I updated the firmware via the SCT website. I also disconnected the batteries on the truck for 10 minutes in an effort to clear the ECM memory. Once I reconnected the batteries I drove the truck in stock mode again to ensure the shift problem was not there, and it wasn’t. I again installed the “street” tune, drove the truck, and the de-fueling/cutting-out was back. I plugged in the SCT again several times and adjusted the Shift Pressure 1-2, Shift Pressure 2-3, and Shift Pressure 3-4 several times to various different settings between -25% and +25%. Originally they were all set to 0%. With the shift pressure settings adjusted there is no noticeable difference in shifting whether it’s set to -25% or +25% or 0%. As long as any of the tunes are installed, the truck de-fuels/cuts out on every shift, every time. The only time it shifts normally is in stock mode.
I’m at a loss since this just started on Thursday afternoon. I've changed the tunes other times before and have not ever had this problem. Other than the new shifting problem the truck drives.
Any help is greatly appreciated; especially with diesel prices as high as they are now since the SCT gives me better MPG.

 

I don't really know much about the SCT.....but I'd definitely be contacting them about this issue. You have narrowed it down enough that it's obviously a problem with the SCT. Either your particular tuner has gone bad......or it's time for an upgrade

 

ztodd377,

In a tow setting the shift points should feel different from the DD or performance tunes. It is normal for them to feel different.


Diane