Trans hunting between 2 and 3

[megastang]

I am having trouble with my wifes trans hunting between gears 2 and 3 at about 28mph. we don't have too much traffic where we live but my wife just took the kids to the shore and in light to light traffic where you are hovering right around 30mph it really can't make up it's mind what gear it wants. I took it out for a drive and logged it, but when I look at the log vs the tune what it's doing doesn't make sense. with shaft rpm around 1160 the commanded pressure will drop from 240ish kpa to like 120 with hardly any change in shaft rpm. In the tune shaft rpm should have to drop to somewhere in the 600 rpm range for it to command 120 kpa. It almost looks like there is some noise on the transmission pressure sensor but it seems to follow the commanded pressure. If someone could take a look at my tune and the log. i've included a pid selection and a dashpage. The trans is a hand me down from my dad and has an unknown DTT shift kit in it. When we first got this trans in the shif tpoints were much too high for our needs. I was able to get them to where they should be using mostly the governor pressure map with just a touch of ttva. I doubt it matters but I did also change the 3-4 map some too.

Thanks

 

[Cbush314]

I have owned two CR's that have had modified trans and they both seem to do this same thing. Makes you wonder what the hell is wrong with your truck, but Lavon Miller told me that even his 2004 CR will still do it. It's just something that you have to drive around if you know your truck.

 

[megastang]

missing transmission parameters/maps

After trying to figure out what could possibly be happening to cause commanded governor pressure to drop like it does I am convinced that there are parameters and or maps related to commanded governor pressure that are not in the standard efi live calibration.

I know there is a way to add additional parameters if you know the address of the parameters. does any one have any information on this?


Thank you !