U0422 error after diff/axle swap

[Brazenbuck]

I've got a 16GTPP, and swapped out the factory 3.73 pumpkin and stock axles for a 3.31 pumpkin and Ford Racing axles. I've tried Forscan and a Whipple flare to change the ratio in the BCM. In either case, once I change the ratio in the BCM to 3.31 I get a U0422 error that I can't clear. If I change the ratio back to the 3.73 the error goes away.

Regardless of the setting in the BCM, the car falls on it's face unless you're barely on the throttle. I've seen many people talk about this problem before you change the ratio in the BCM, but never after. Anyone seen this before?

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[Elit3Sally]

I am having kinda of the same issue i went from 3.15 to 3.31 and I can not get it to work for me.

 

[ctandc72]

I am having kinda of the same issue i went from 3.15 to 3.31 and I can not get it to work for me.

I switched the OEM 3.15 gears in my '17 (it had @ 2K miles on it LOL) to a complete 3.55 differential. I GPS Verified the speedo being correct BEFORE and AFTER the swap with NO changes made whatsoever. The ABS / Wheel sensor will pick up the difference in rotation of the wheel and adjust itself. I DID change the BCM to 3.55 with FORScan after the fact, because I was already in there, but it didn't need to be done as I have a 6 speed manual car so of course my shift points are controlled by me.

I assume you have an auto car.

As for the DTC - this thread might help:

https://www.mustang6g.com/forums/showthread.php?t=67564

 

[olaosunt]

Bringing this back from the dead as having the same issue .
Not sure if could be causing high rpm break up /shifting issues .
Was there a solution?

 

[BmacIL]

I've got a 16GTPP, and swapped out the factory 3.73 pumpkin and stock axles for a 3.31 pumpkin and Ford Racing axles. I've tried Forscan and a Whipple flare to change the ratio in the BCM. In either case, once I change the ratio in the BCM to 3.31 I get a U0422 error that I can't clear. If I change the ratio back to the 3.73 the error goes away.

Regardless of the setting in the BCM, the car falls on it's face unless you're barely on the throttle. I've seen many people talk about this problem before you change the ratio in the BCM, but never after. Anyone seen this before?

Leave the ratio as it is stock in the BCM. Your speedometer will be accurate based on wheelspeed.

 

[olaosunt]

Leave the ratio as it is stock in the BCM. Your speedometer will be accurate based on wheelspeed.

I am now getting the same code after swapping to a 3:31 rear on my A10 18 GT/whipple .

I did change the the ratio in the BCM but when I put it back to the original 3.55 I am still getting the code .

Car started sifting funny(hard to explain but I went from trapping 140 to 110 mph in the 1/4) after the swap . It would also break up at high rpm doing a pull in any gear .
I thought it could be the clutches in the auto and upgraded them but still having the same problem .
Swapping the plugs seem to fix it for a short while but it’s returned and my plugs were not fouled .


I was hoping it is an issue that can be fixed by my tuner (Rob@PBD) as Lund tunes cars that have swapped their rear ends are not having the same issue

 

[Bluemustang]

I went from 3.15s to 3.55 Torsen diff housing and didn't make any other changes. Car has full power in all gears and speedo is all good. I'm an Auto car as well. Maybe try undoing the changes you made? I wonder if that'll help.
Just wanted to share my experience.

 

[TX-Ripper]

You have to use the relearn feature that was added to forscan a couple months ago

It tells the pcm and bcm to get on the same page

 

[olaosunt]

You have to use the relearn feature that was added to forscan a couple months ago

It tells the ecm and bcm to get on the same page

Thanks. Did you swap your rear end and did this work for you ?

Never used it before but went ahead and orders the forscan tool.

It seems complicated but I am sure I can figure it out . Lol

I am pretty sure the whipple tool I used makes changes to the BCM and may be the PCM if I ran their tune (might try it just to see)
Not heard back from my tuner but others have been able make changes so you don’t get the code

 

[TX-Ripper]

Thanks. Did you swap your rear end and did this work for you ?

Never used it before but went ahead and orders the forscan tool.

It seems complicated but I am sure I can figure it out . Lol

I am pretty sure the whipple tool I used makes changes to the BCM and may be the PCM if I ran their tune (might try it just to see)
Not heard back from my tuner but others have been able make changes so you don’t get the code

I swapped from the 3.55 (pp1) to a 3.15 rear.

Changed the gear ratio data and got that code, then found out there is a relearn function that has to be run to to get the pcm and bcm linked

 

[Tommy V]

Guys stop trying to change the data in bcm.The speedo does not work off the abs wheel.speed sensors.It works off trans output shaft sleep sensor znd will automatically relearn.If you change bcm data you will have nothing but problems and have to resink the bcm and other modules.This has been posted many times for the 15 plus cars.Bcm has nothing to do with speedo.

 

[Momogt26]

So if I swap my 3.15 to a 3.31 or 3.55 just leave it alone and the speedometer will correct it's self

 

[Tommy V]

So if I swap my 3.15 to a 3.31 or 3.55 just leave it alone and the speedometer will correct it's self

Yes that is correct.

 

[Momogt26]

Yes that is correct.

Thanks

 

[BmacIL]

I swapped my 3.31 clutch pack diff out for a 3.73 torsen. Touched nothing with the tune or BCM. No codes, no power limiting, no speed limiting/issues. It's just fast and puts power down way better.

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