hotrodjohn71

I would like to permanently disable the adaptive learning feature of the automatic transmission in my 2006 Mustang GT. I have read that in older model mustangs, a relay of sorts was built to pulse the ECU every time the ignition switch is turned on to reset the transmissions adaptive learning but maybe someone knows of another way.
How can I get around this feature?

jwog666

why do you want it to forget the learn? its there for a reason, not only does it learn driver information, but it also learns the clutch apply times as the transmission wears, so it can keep shift quality consistent

hotrodjohn71

Hi Jwog666,
I have this slight hesitation between second and third gear on upshifts. Might be called a surge. Its annoying. I have found that disconnecting the battery and resetting the ECU will fix the issue and the car will shift like a dream for several days.
The car is getting used for mostly slow speed stop and go city driving so the adapt is learning that but it never used to have this issue when it was newer.

movielover40

My Mustang has had that hesitation for years. Doesn't seem to affect anything.

jwog666

what that is is the pcm backing off the throttle a bit, then the trans shifting to the next gear, then the pcm getting back into the throttle. its how it is designed to work. its best to not try to re engineer a car to fix a perceived concern that isnt a concern. if you want the shifts to firm up a bit, i would suggest a tuner, most have provisions for what boils down to a shift kit for the modern trans

hotrodjohn71

Thank you, that makes sense. I will look around for a tuner who can do that for me.

jwog666

sct is the way to go, and with this tuner, if you decide to do some major mods in the future, its supported virtually everywhere so it can be reused for custom tuning.

https://www.sctflash.com/Products/pr...cleEngineId=43

Norm Peterson

Yeah, old thread. But I think John's complaint is centered around the amount of time certain upshifts are taking, not the firmness.

That it's something relatively new suggests that something has changed somewhere in the 100% OE powertrain and its controls. To me, that makes an aftermarket tune solution more of a band-aid unless it also turns off the learning.

Now it could just be that John's current driving is slower and milder these days than it used to be, in which case the cheap diagnostic would be to find ways to drive it harder more frequently just to keep the adaptive learning from assuming that 3rd gear is just for coasting along (making prompt engagement unnecessary).


Adaptive learning is fine . . . but only as long as it works with the human driver and fits itself to his 'pace' without any warts like this one.


Norm

Derf00

Having learned a lot about the 5r55S last year when I did some light work on mine I'm going to suggest either replace the valve body with a remanufactured one or get a shift kit for the existing one.

A tune won't resolve the problem as Norm stated. It will be a temporary fix by increasing the tranny fluid pressure. I'll explain why below.

The valve body is in charge of directing fluid inside the transmission to get the gears shifted as directed by the Solenoid block which in turn is controlled by the PCM. It does this through a complex series of pathways machined into solid aluminum block. Each pathway contains a piston and spring(s) that rely(ies) on pressure to move the respective piston and initiate the shift or torque converter lockup.

The problem is these valve bodies are aluminum and the pistons are steel. So, when you have two surfaces that rub against each other constantly you get wear in that the valve body piston bores start to get slightly larger or out of round. This allows pressure to bleed by the piston thus preventing the transmission from shifting as expected (this could be in the form of how long the shift takes, how firm it is, whether it holds the gear properly or not and many others). The only way to truely address issues like that are to get a remanufacturered Valve Body, not new. New will have the same issues. Remaned fix the most common issues.

Also do not waste your time/money/effort on a used one. It will most likely have the same or worse problem than yours. If the aluminum is worn the valve body is toast. Yes you can use over bored pistons but without the proper jigging equipment to re-bore and/or sleeve the cylinder you will destroy your transmission with the micky-moused valve body.

One other thing, when was the lats time you changed fluid? I don't care what the manual says, 30K intervals is recommended to keep the 5r55s performing at it's best.

Start with the fluid, you can have a shop do a proper tranny diagnostic for about 100. This includes driving it with a pressure guage(s) installed to monitor the pressures as the transmission is driven. Each gear and shift must meet a specific range of pressure, over/under that range pinpoints the problem circuit in the valve body or in the shift process.

hotrodjohn71

Thank you guys for your comments. I'm still following this thread.