Results 1 to 4 of 4

Thread: possible to stop the 4T56E from going to max pressure and shifting hard?

  1. #1
    Potential Tuner
    Join Date
    Aug 2007
    Posts
    2

    possible to stop the 4T56E from going to max pressure and shifting hard?

    Anyone know of a way to stop these transmissions from always going into some kind of safe mode that causes them to shift hard? Every single one I have had seems to always go into some safe mode that ramps the line pressure and makes then shift hard, They shift nice for a while then starts slamming threw the gears. i have even done the work to replace all the shift solenoids hoping to stop it. I figured there would be some kind of table that could be modified to never let it go to max pressure but I can't find it. There has to be something that tells it to do this. This car is a park avenue ultra that Im messing with now. Thanks in advance for the help

  2. #2
    Senior Tuner TheMechanic's Avatar
    Join Date
    Jan 2014
    Location
    SoCal
    Posts
    1,533
    You could try BlueCat. Not positive if it works on trans-axles but it may. Also are you getting a corresponding P07XX code when it starts shifting harsh? You are not going to get that with stock programing unless commanded as a fail-safe.

  3. #3
    Potential Tuner
    Join Date
    Aug 2019
    Posts
    4
    A couple months late but you can bump up the upshift shift pressures, multiply them by 1.2. This will speed up the shifts without making them rough, what?s happening is the pcm is detecting a shift that is taking longer then 0.6 seconds and it can?t get it under that, so it sets p1811 and commands max pressure.

  4. #4
    Also if you disable the code it won't go into max adapt anymore either. It's P1811