Down-Shift Issue

[JSimcik]

When running at normal engine speeds at higher highway speeds (Lets say <2000 RPM, <75 MPH.), a sudden WOT input causes a down-shift - kinda.

The transmission tries to grab 2nd (probably 2nd-Prime), but shudders badly. It acts as if it is not fully in gear (or it is running in both 2nd and 2nd-Prime). Staying in the throttle does not help, and the shuddering continues. Dropping throttle below WOT and allowing the tranny to up-shift to what feels like 3rd (1:1, not 2nd-Prime) eliminates the shudder, but limits acceleration.

This has also happened on a few occasions when at lower vehicle speeds, but always when making the 5-2 kick-down.

This is a very unnerving feeling.

Please let me know what needs to be done to resolve this.

[mikel]

Have you ever attempted to duplicate this with the stock tune?

[JSimcik]

Yes I have. I was unable to duplicate the problem.

[JSimcik]

Mike, any word on this? It happened again yesterday - twice...

[JSimcik]

Mike, this is still occuring!!! I have done some experimenting, it only happens while in 2nd-Prime!

Either a downshift to, or just selecting 2nd-Prime (which, as discussed in an earlier post, is "3" using ERS with the DS tune installed) and then accellerating with more than ~70% throttle will cause the shudder!!

Turning Tow/Haul ON, or removing the DS tune eliminates the problem!

I would bet then, that this has something to do with the relabling of the gears used by DS - maybe only part of the system is changed, not all of it - and the transmission is trying to run in two gears at once, or is trying to downshift to 2nd-Prime when it's already there...

I will try to log this if you need me too, but I really want to get this fixed ASAP!!!