Adjusting Tire Size with FORScan

[@lukas1698]

Wow i cant believe this doesnt have more views. Watched your intro to forscan video then this one. Works like a dream! Was adding fake kilometers to my 2021 f150 because my winter tires are smaller and no dealer or shop would fix it for me. Life saver!

[@mr.diyourselfchannel4343]

Let me just say you are a blessing I don’t know why you don’t have more likes so I listened to how u calculated everything and my mm was 2697 and just listening to u I just set it to 2650 and bam it was on point thank you so much I needed this cause I am going on road trip have a blessed day

[@AutoDad]

Thank you for the wonderful comment. Sometimes with KZbin it takes a while for a video to really make it in to circulation

[@rwooley4494]

so I know this is an old but very useful video. I have purchased a f150 with a 3" lift and bigger tires 35/12.50R20's and can not for the life of me. Searched the circum. and shows 2794.76. Made the change via forscan and it took the new circumference but at 60 im still going 6 over. thank you Auto Dad !

[@69airride3]

Your videos have been very helpful to this new owner of a 2017 SD. I downloaded Forscan and purchased the OBD connector you suggested. I needed a couple of sessions to get comfortable with the software and I have made some changes to my truck successfully. In your video you received an audio message in regards to your 911 system needing service. My truck is an XL, no Sync, no Bluetooth, no Navi all I have is AM FM and a CD player. The question I would like to ask is, if you know how to address the 911 audio message you are receiving. My problem is kind of a similar issue, when I start my truck up and when I shut the truck off I get an audio message like your 911 message but in French. Upon start up I am pretty sure it is saying to "updating system please" and when I shut her down I have no idea what the message in French is. Yes I have done all the language settings in my dash and radio menus all of the written words are in English it is just the 2 audio message I receive in French. So I was hoping you might be able to tell me if there may be a solution using Forscan. Once again Thank you for your videos they have been very helpful. Sincerely

[@HotRodsDFW]

What year was your 2:14 truck? I mean was it a 10 speed superduty 6.7?

[@shaskhim]

Great job! Does any body know how can i do it on KIA & Hyundai? I've searched a few days, but didn't find something helpful for my KIA Picanto yet. I've just changed the tire size and have some problem with the speedometer. Any helps on this would be highly appreciated.

[@scottyjordy]

Great video! I have a 2019 Ford F-150, attempted to do this both ways using the tire size spreadsheet and the circumference. Both end up throwing the wrench alert and check engine light. I have reset the PCM Module Reset, the TCM Reset All Adaptive Tables and TCM Clear Transmission Adaptive Tables. After that I reset the DTC which clears the wrench signal. But then I am left with PCM CODE: P0630, PCM CODE: U0422 & OBDII CODE: P0630 that leaves the check engine light. Anyone have any advise?

[@masontanner1779]

I did mine today and no matter what I can’t get them to go away unless I reset back to the original size. Super frustrating

[@BlazeofFire524]

Just did mine I get the same thing. Another thing I don’t understand is my original tire size which I haven’t changed at all was larger than what I have now. I went from 265/55/20 to 275/70r18 circumference increased significantly.

[@dmiller7889]

​@masontanner1779 what was the original size in forscan I lost the paper and can't get mine to go away.

[@Howardhandupme]

When i did mine on my maverick, my car went crazy. Lights and chimes. Got a code for p160a. Body control module inaccurate data. Had to do reset to clear and force module to accept new tire size. Scared the shit out of me at first thinking i broke my car. But after reset doing fine.

[@gadielsantiago8813]

"I hear you" ahh that annoying sound and one starts talking to the truck, same here lol

[@gutierrezc8709]

I have a 2011 f150 with 325/60R20s, input 2819 mm for circumference. It did not change the speedo. Its still traveling faster than speedo says. Speedo set to 45mph but the actual speed is 49 mph.

[@andref713]

What speed app did you use?

[@clintwhitsell27]

I have a 22 F250 with 37's. I keep reading the later models are not changeable. What year is your truck ?

[@AutoDad]

2017

[@evosarebetter]

Did you figure it out? I got the fault code P160A

[@patrickkissel206]

I purchased the ELM327 cable for my 2010 F150 FX4 but I only get 4 things that I can change and nothing more. Am I missing something? Appreciate the help.

[@AutoDad]

I think it has to do with the options available for that year. There may not be a lot to change

[@patrickkissel206]

@@AutoDad Thank You!

[@dylanwhite3880]

Does this work if you made your tires wider and does this void the warranty or should I just get different wheels

[@AutoDad]

This does not void your warranty

[@drewabad11]

I downloaded the latest version and Tire Circumference is not listed.

[@davidadelson7982]

Looking for help. I have a 37x13.50R 20LT and looking for the right conversion

[@AutoDad]

Just use a GPS app and make small changes until it matches

[@marcusbarnes5929]

Does your odometer and fuel economy read accurately after changing the tyres size diameter?

[@AutoDad]

Yes as they all read off of the same source

[@marcusbarnes5929]

@@AutoDad on the Australia ford rangers the factory odometer reads 100 on dash and 96 on the gps with stock size tires 265 65 17. When putting on larger tires 285 65 18 it reads 100 on dash and 100 on gps but the odometer is out buy 8% which throws out DTE and shift points in the auto.

[@AutoDad]

That is weird

[@varmint223]

So I adjusted and it seems to not be staying true must be my gps being off it keeps jumping around

[@SirGriz1974]

I'm assuming that this will also correct the MPG difference that goes along with changing tire size?

[@AutoDad]

It should correct your DTE calculation

[@urntwrthyZ]

TireRack provides the circumference for each tire they sell.

[@DavidGutierrez-zi4dy]

thanks

[@wandypaulino210]

Hey great video! Quick question by doing this I dont have to tune my truck or re gear? I planning putting 33x12.5r20. Currently stock is 275/55R20.

[@AutoDad]

No. This program has nothing to do with the ECU

[@wandypaulino210]

@@AutoDadokay tysm!

[@johnpullen5793]

I’m trying to change my tire size configuration I enter my gear ratio then tire size on my 2000 F250 diesel and it did not download it says error writing block failEd incompatible configuration how do I get past that?

[@AutoDad]

Don't change your gear ratio. Just change the circumference

[@kiddt1999]

I did this and now i have a check engine light and a wrench that says see manual. Using forscan also to clear it and it won’t clear. Help!! I had to revert back to stock size then cleared the codes and they went away. Anyone know how to do this on a 22 f250???

[@cjortiz1182]

You ever fix this? Tried changing the tire size and it gave me a service advantrac light so I changed it back to the factory size

[@dcbatman25gaming96]

I have a extended license and can’t find my BdyCM what could be reason

[@NastyZZZ28]

Do you have the dual switch cable?

[@tim6986]

ya don't go by just tire size, each manufacturer can very actual size of tire. the whole "run big" thing is real, and that'll throw off your circumference. look up actual tire manufacturer specs.

[@brandanroberts4366]

So I did this. My tire size is 285/65/20. Circumference is 2760. Before I changed it my spedometer showed 3mph slow. I changed it to 2760 and it’s showing 3mph fast now. Unsure what’s going on

[@AutoDad]

I had to tweak mine. Cut the change you did in half and you may be close

[@danadams3362]

Hey, what app are you using to measure your speed?

[@AutoDad]

Check out "GPS Speedometer and Odometer (Speed Meter)" play.google.com/store/apps/details?id=com.coolniks.niksgps

[@danadams3362]

Thanks for the quick response. Love the videos!

[@JoelGarcia-vz5we]

nice job!

[@Adabulldoya]

I’ve heard you can get faster by changing the size does anyone know how or what size. I max out at 105 I’ve heard you can get 117

[@steventurner5260]

Can anyone help I need tire circumference for 285/75/r16

[@jerryblakefield5942]

I jsut plugged my OBD2 adapter. The Forscan software is telling me I need the extended license, to make changes. anyone know why it is telling me this or how to get around it?

[@AutoDad]

Watch my other videos. You need a license to make changes

[@gerardblakefield1367]

@@AutoDad thank you. I realized I had the license, I just hadn't entered it.

[@rockeyoliver7254]

Awesome video! To bad Forscan has locked down the website and membership. I’m getting a 2023 coach on a E450 (7.3 V8) chassis and want to do some changes in the system.

[@airtechmech6681]

It's not locked down now.

[@xGR1MxREAPERx]

It still works and is free? You don’t need a payed version to adjust this. It’s all free. You just need a cable or way to read it

[@Stevefrom859]

I’m wondering why mine doesn’t have the tire size readout, only circumference in mm?

[@AutoDad]

Just calculate the circumference. Test and adjust as I did.

[@nigelbanderas5193]

Mine says the mm is outside of limits? What do I do? 21 f150

[@AutoDad]

Will it still take it?

[@getaway_man]

Why don’t I see tire circumstance? I see it in (MAIN) but it doesn’t let me manually enter a number.

[@AutoDad]

Every vehicles options are different. You may be able to select a tire size for yours

[@thejourneymen7722]

You better check the forscan form you can’t just change the tire circumference there are two other modules that have to be changed also or they will fight with each other.

[@AutoDad]

I have had zero issues

[@Airthube]

What are those modules?

[@AutoDad]

Just the Body Control module

[@Airthube]

@@AutoDad I did that and got PCM and TCM errors! Can’t reset TCM message! What should I do?

[@AutoDad]

Thats weird. I would revert it back and then check on a spreadsheet and see if there is something else. Mine was only the body control module

[@readymarian]

Thank s to russian people man enjoy !

[@kristinemayer346]

I tried this on my 18 3.5 and after changing I got the wrench come up. I reset it but any idea why?

[@AutoDad]

Sometimes it doesn't take the change or like it. Sometimes it just messes up

[@kristinemayer346]

@Auto Dad should I retry? I have bf goodrich ko2 275/65R20 and I think the 2718mm is correct, anyway to know for sure?

[@sc8106]

@@kristinemayer346 you have to use the relearn functions on the PCM and TCM after you input the new tire size on your BCM. Your basically recalibrating the data in those modules to be compatible with your new values for your tire size. Once you do that the wrench will go away and you can clear the DTC codes. There’s better information about how to do this on the f150 forscan forums.

[@ThatBoyMichael1]

@@sc8106 not everyone does this tho

[@marcusmora73]

why did you change mm vs tire size?

[@AutoDad]

In my application it would not allow me to change to the tore size I have. There was not an option listed.

[@marcusmora73]

@@AutoDad I thought i saw it in this video. or was it stock tiresize just off on speedo? Thanks for the reply, this is fun geeky stuff.

[@AutoDad]

I added bigger tires and the option for my size was not listed so it was easiest to just tweak the circumference

[@smokendt]

I see that Forscan wants the size in mm, but will it let you adjust actual tire dimensions that was listed below that line. 275R 70 into a 35 12.5 20? or do you just leave that alone?

[@AutoDad]

Just leave it alone. I tweaked the mm until the gps matched

[@ypautomotriz]

thank boss.

[@guyonthecouch007]

The mph might read different when the app uses gps?

[@AutoDad]

I used 3 different apps, 2 of which I tested prior to verify accuracy

[@danadams3362]

Just noticed the version of Forscan I am using doesn't show the tire size??

[@AutoDad]

Try updating it

[@danadams3362]

I just downloaded it last night??

[@AutoDad]

Maybe it doesn't offer it on your specific vehicle. I would check w spreadsheet and see if you can change it in the AS BUILT

[@danadams3362]

Ok. I am using it on my 2020 F150 XL. I will try and find the spreadsheet to find the info and try the AS BUILT entry.

[@jmaster0027]

@@danadams3362 Same issue on my 2018 lariat. Did you ever find a solve?

[@gabrielvalerio1396]

i did this on forscan and now i’m having a wrench popping up and dtc of p160a on my 17 f150

[@pikamon.77]

How do you fix this problem?

[@gabrielvalerio1396]

@@pikamon.77 do you have a 10 speed transmission?

[@evosarebetter]

@@gabrielvalerio1396 Did you figure out how to fix?

[@gabrielvalerio1396]

@@evosarebetter it depends if you did all the steps he mentioned and still didn’t work i reset the tim and clear the value and it went away but since i did that i still get the mismatch on obd but doesn’t turn on the engine light on

[@gabrielvalerio1396]

@@evosarebetter it depends if you did all the steps he mentioned and still didn’t work i reset the tim and clear the value and it went away but since i did that i still get the mismatch on obd but doesn’t turn on the engine light on

[@Stoic_optimist_realist]

FROM THE FACTORY your speedo will read one to two MPH faster than you are actually moving - factory trying to give you a little wiggle room on not getting a ticket.

[@henryhiggins2021]

2600mm tyre circumference. That's massive, I think you have conversion error there.

[@NastyZZZ28]

Not really. That’s roughly 102”. Remember that you have to do the diameter times pi.

[@inspectitaustin3545]

@@NastyZZZ28 Hey could you explain please how you got the 2600 mm tire circumference? Every watched your video and I’ve entered it in several different ways. I have 43 inch tires and I’m trying to come up with a tire circumference

[@NastyZZZ28]

@@inspectitaustin3545 so to get circumference, you multiple the diameter of the tire times pi. D*pi. 43 inches x 3.14 I’m getting 135” converted to mm is 3429mm.

[@varmint223]

My speedometer is off truck says 50mph gps says 58mph

[@dr.voltsgarage689]

I want to have a picture asbelt

[@High_Octane]

This is the wrong way to do this.

[@luke8222]

Why?