FORScan forum

captainsdc wrote: Fri Oct 25, 2019 7:07 pm I wonder if this is where I may have to go with my 2013 F150 with the 3.73 trans and new 275/65-20 K02 tires (stock were 275/55-20).
Ramky27, where did you find the min allowable revs/mi (tire size) per your transmission?
My GPS gets off if I drive long enough so I know the tire size change is what did it.
Scott

ramky27 wrote: Sat Aug 31, 2019 4:18 pm

josephj22 wrote: Fri Jun 28, 2019 1:47 am Then I followed the advise here and checked the live ID of tiresize Rev/mile and found the following:
- on original tire size: 683 Rev/mile equivalent to 30.5" tire
- on updated tire size with p1635 code tire size live value: 664 Rev/mile, which means that this is the minimum acceptable Rev/mile for TCM.

Thank you so much. Your post above helped me no end.

I have the 2016 3.2 Ford Endeavour (in India, the Everest is called by that name due to trade mark issues). I gave her brand new shoes upsized from 265/60/R18 to 285/60/R18.

When I tried changing the hexadecimal value for tyre circumference from 0934 to 097E, it threw the same error code. I followed the exact same procedure you mentioned and corrected the value to read 0977 which equates to the minimum allowable revs/mile on my car too (664). Now all error codes are clear and I am satisfied the tyre size has been updated.

Yet to compare the GPS speeds though. Thanks once again guys and to FORSCAN. You saved my day.

I also have a 2013 and have tried multiple times to change the Tire size to the 315/70R17 (Raptor Tires) and it will not update. Have you had any luck updating this? I currently have the U0422-2F Code but no others in PCM or other places.

Mikegfx4 wrote: Tue Aug 04, 2020 1:56 pm

I also have a 2013 and have tried multiple times to change the Tire size to the 315/70R17 (Raptor Tires) and it will not update. Have you had any luck updating this? I currently have the U0422-2F Code but no others in PCM or other places.

Same issue here.
2014 F150.
Stock size is LT275/65R18
Current installed size is LT285/75R18
Changed as built code using spreadsheet calculator & performed PCM relearn. Speedo does not change and sets U0422-2F. BCM menu shows invalid as expected because it wasn't a factory size. Thought maybe it didn't like my as built code.
Changed menu tire size to 315/70R17 & performed PCM relearn. Speedo does not change and still sets U0422-2F.
Changed tire size back to LT275/65R18 & performed PCM relearn. U0422-2F is gone.

Hoping someone else has this figured out a way on 2013-2014 F150 to get it to accept a size different then it left the factory with.

I'm just living with the code since it seems to be accurate now and the wrench isn't showing...
S

I have a 2019 Ford Expedition and anything other than stock seems to throw a wrench. Hopefully one of the very smart people here figure it out I'll send them a case of beer when they do

2019 F150 SCREW, FX4, 3.5EB.
Stock tires were 275/55R20, installed 275/65R20.
Stock was 2462mm, the new tires 2718mm and 2.5 mph high. I was getting the UO422 error message. I moved the input to 2631mm and am now 1 mph low and no PCM UO422 errors.

2019 f150 super crew xlt
Changed my wheels and tires out today. Used forscan to make the change but I used the easy method to simply enter the circumference (2644) and got the u0422 error as well. I tried changing it to 2631 to see if it would clear but it didn't, even after a PCM relearn.
No CEL but idk if driving around like this it's ideal.

Traxx, Hhow did you come up with the 2631 number?

I went from stock to 275 70 R18 btw
Also got some rubbing going on too ( just throwing that in)

So I’ve changed the tire size in both my dads trucks one 6r80 other a10 and also my a10 mustang along with axle ratio since I upgraded to the gt350 3.73 torsen. The U codes don’t affect any driveability or trigger the check engine light however what I did myself for all 3 cars is the following which cured any weird issues I was having with shifting and or cutting power due to the P code it throws. After writing the codes into the 726-12-01 I stopped the service procedure once it completed the changes, followed with the pcm relearn (it does clear the code completely the reason its still there is you have to then go to the DTC tab and clear it ) also clearing one of the other U codes that are there they all disappear but come up when checking on them but none of those will cause any issues as far as I can see. The last thing to do is in the wrench tab for service procedures (clear adaptive learning tables it only takes 5 seconds for that one and this will be essentially what makes it shift smooth after a few miles of learning everything again and all power will be back once the procedure completes with mixed driving cycles) I want to say mine cleared all drivability issues I had in about 100 miles driven I’d call that a win and applies to 2015+ vehicles since my dads trucks are 2015 and 2018 hope this helps!

For those of you with an 2017-2020 F150 with 10 speed check my post here:
viewtopic.php?p=68424#p68424

the problem people are having is theyre exceeding the max tire circ. allowed by pcm. if theres no way to change this with forscan or see this then you just have to guess and hope youre under your max allowed. i have a 2020 f150 limited and my stock max was 2678, yours might be the same or close. if i put 2677 for tire size im good with no light or wrench. if i exceed that i get wrench. this max number can be changed with hp tuner but that cost $$$$. so using forscan you can keep putting a higher number in until it sets code. go back one number, clear dtc, and youll be close. withouit being able to raise that max tire circ. whatever the max is on yours is the highest you can go without setting code or wrench. hope this helps and didnt confuse anybody.

per previous post. If you live in the Phoenix Az area, i might be able to help.