new $EE tuning thing!

[fbody_Brian]

So what do you imagine this OS Code hack is for high stall OBDI?

http://ls1tech.com/forums/lt1-lt4-mo...l#post17162485

http://ls1tech.com/forums/lt1-lt4-mo...l#post17032019

[steveo]

So what do you imagine this OS Code hack is for high stall OBDI?

ed says some odd stuff sometimes.

thing is, that thread talks about disabling the VSS error code, not moving the 'RPM threshold', they might be different. i'm not even sure that 'rpm threshold for vss error' or whatever is an accurate label.

The fix is NOT the VSS error code. Moving the WOT mph threshold for the 1-2 shift down to 1 mph and letting it shift on the rpm trigger was the fix for mine.

this seems reasonable too.

[lionelhutz]

ed says some odd stuff sometimes.

thing is, that thread talks about disabling the VSS error code, not moving the 'RPM threshold', they might be different. i'm not even sure that 'rpm threshold for vss error' or whatever is an accurate label.

this seems reasonable too.

I already described this one. Setting the upshift mph in the kickdown table to 1mph and then using rpm only fixes the kickdown mph being too high. Obviously, you don't have to use 1mph, but the speed the car reaches at WOT has to go above the shift mph before hitting the rev limiter or it hits the limiter instead of shifting. This IS NOT the same as the stall wall where the transmission goes into limp mode.

Another stall wall "fix" is to put the 100% TPS 1-2 upshift mph in the main shift table to 1mph. I don't really understand why this one would work. At WOT the PCM is using the kickdown table values, not the main shift table so the 100% TPS mph setting in the main shift table should mean nothing.

[fbody_Brian]

... but the speed the car reaches at WOT has to go above the shift mph before hitting the rev limiter or it hits the limiter instead of shifting.

I always found it odd the way it's set up by default and just lowered all my kickdown shift mph settings really low in all gears so I can just specify an rpm for shift.
good to know about the TPS 1-2 upshift mph in the main shift table!

[steveo]

this is all great info, keep it coming. im learning a lot.

i dont really want to tune automatic transmissions but understanding how they work is really useful for my tools.

how about 'adaptive pressure' thing? is that slip measurement that increases line pressure to compensate? or...

how does that work?

[fbody_Brian]

I found where I read about the v4p towing package trans tables...
it was on this forum. LOL
http://www.gearhead-efi.com/Fuel-Inj...ission-VIA-PCM

Also buddrow who is active on here seems to have some knowledge about how transmissions work so maybe has some insight.
http://www.gearhead-efi.com/Fuel-Inj...mission-tuning