EFIDynoTuning Forum

Think I may have found it. Will validate later today.

VS_SH_VAL2 = Minimum vehicle speed to validate an upshift to 2nd gear.

careful with the shift points. I'm not sure if the trans can physically do it but you'd pop the engine if it shifted into the wrong gear at some outlandish speed. (scenario where road speed and the shift don't match such as 9000 engine rpm or etc. )

Yeah thanks for that. The goal is to keep the transmission from shifting into second when the OD lockout switch is on. I wrote code that has replaced fn12s and now VS_SH_VAL2 and is working great except once the speed and RPM become stable something else is forcing the shift. I did not want to modify the main shift routine, but I may have to if I can't do it with calibration constants.

Looks like shift validation is only about sending trouble codes for missed shifts. I tried forcing GR_DS to 1 but it keeps shifting up and down. Looks like I'll have to bypass the code. Is setting tstrat while driving even advisable?

No you definitely can't change the trans strategy while driving

what are you trying to do exactly?

I simply want this:

If in first gear and od lockout switch is on, do not shift into second gear under any circumstances.

The point is to be able to lock the converter in 1st gear. The E4OD in manual low is hydraulicly unable to lock the converter. I need to prevent shifting into second with the selector in Drive. I have it mostly working by just setting fn12s to 125mph but as soon as rpm and speed stabilizes some other logic is forcing the shift.

if pullin is exceeded it will

make a new thread for your truck with vehicle details and post your tune, ill take a gander and see if we can get it figured