Adjusting for Bigger Tires in FORScan for your F150

[@SmackeysGarage]

Tools/Software Used: OBDLinkEX Adapter: amzn.to/3QOBmDC

[@slimjam44]

Mine is a 2015 F-150 XLT, just hit 60k miles. I switched to all led bulbs. The turn signals blink normally but the underdash click sound is fast. My understanding from your vid is that's okay if the sound doesn't bother me? Also, I'm going to get the obd link and get bambi mode fixed because we moved out south of KC and do a lot of hwy driving now. I just found your channel and subscribed. Thanks for all the info, I really appreciate it! John W., Louisburg KS.

[@SmackeysGarage]

@@slimjam44 If All the lights are working correctly then I guess it's ok. With the OBD Link and FORScan you can disable the bulb outage fast blink and bring it back to normal. There should be settings for both front and rear. Otherwise, you can always add resistors to bring the current up. Thanks for watching John. Appreciate i!

[@colt-ss3lw]

@@SmackeysGarage I have 2 questions ...... Will forscan tire size programming work on 96 bronco OBDII. I'm just not able to get the correct number to put into psom. I get 2 different numbers for Toyo 265/75r16 at III 116T. Toyo says 656 and Tire size says 638. I am using inches for this manual programming. Should I divide the difference of 18 and enter 647? I only get 6 tries and have 4 left. I'd like to get this done next week 5/7/24. Any suggestions would be appreciated since the ole timers have all retired and no one has a clue.

[@jamesreese3937]

For those asking! A dramatic change in tire size can/will affect transmission shifting and a sort of "dogging down" at highway speeds. It isn't actually "dogging down" but may require more throttle to maintain speed, and/or cruise control may have a harder time maintaining speed. This will fix those problems! Also - the reason his speedo is still slightly off - is because the tire circumference will slightly reduce (by ~3% at these sizes) when truck weight is put on them. You'll notice that the default setting in your truck has already accounted for this and is slightly lower than the original tire's actual circumference. To account for this, reducing the # in mm of your new tire's circumference by ~3% will make the speedo basically perfect.

[@ericpena3426]

Doing gods work. Thanks a lot

[@ericpena3426]

To get the transmission to learn this properly do I just adjust the size of tires or do I need to do something else?

[@jamesreese3937]

@@ericpena3426 Once you adjust the tire size - the transmission should start to act normal again. You could also perform a "re-learn" on the transmission - but it's not really necessary.

[@CuursLight]

For anyone who’s going from 18s to 20s. I put my tire mm to 2528 and it’s spot on . 2631 was off by 2-3Mph as he mentioned in the video. 2023 F150

[@SmackeysGarage]

Thanks for letting everyone know!

[@alexa.1927]

I couldn't find that precise info I was looking for anywhere else! Thank you so much for this! For reference, I was going from 275/55R20 to 275/60R20 like in the video but still found it off too by around 5% when I entered 2631.

[@SmackeysGarage]

@alexa.1927 glad you found the info!

[@CuursLight]

@@alexa.1927 Did 2528 get the speed correct?

[@alexa.1927]

@@CuursLight I entered 2547mm and it gives me the exact same speed as my phone’s GPS. After replying to your comment I saw an other comment from Smackey saying that the stock numbers for 21+ f-150 with 20s were 2541 and that’s the one I decided to try first. I ended up not trying 2528 but I might do it when I have time for comparison.

[@ScottSanford-pe7xg]

I just used this video to calibrate my speedometer after getting new, bigger tires and it worked perfectly. Reducing the total mm of the circumference as suggested in another comment, my digital speedometer, regular speedometer, and the GPS speedometer all match. Thanks for the video!

[@SmackeysGarage]

Glad to help!!

[@hzardiswastez]

Thank you for the video! I used fordscan like 4 years ago and am rusty. Your video was straight to the point, well articulated, and overall informative. I sincerely appreciate it. Thank you!!🙏

[@SmackeysGarage]

Glad to hear you appreciated my video style!!! Welcome

[@SmackeysGarage]

I got feedback from a viewer that the stock settings on an F150 with 275/60/20 is 2547mm. That might make a good starting point rather than just using the calculator directly. Keep in mind, different tire pressures may cause this # to be slightly higher or lower.

[@trixerbautista6766]

Any magic number for 275/65/20

[@saltydawg8988]

Glad I can do this myself! Got my off road tires taken off after hunting season, and it’s way off now. Thank’s for this video

[@SmackeysGarage]

You bet! Not too hard to readjust

[@andresmith8693]

Dude, big thanks for the easy to follow guide. My wife is a speed demon so this would really help us in not getting a ticket. I cant imagine what the stealership would charge for maybe 30 minutes of this computer work, those clowns already hurt me with the $400 for an extra key!!

[@SmackeysGarage]

Haha glad I could help!

[@dougrobertson3508]

Very clear instruction. Just put 35's on my 18. Thanks!

[@SmackeysGarage]

You are welcome!

[@darius326]

Hey, I’m about to put 35s on my 18 as well. Did this fix help your transmission shift when it’s supposed to?

[@dougrobertson3508]

@@darius326 Not sure what you mean about the transmission. I have no problems in that respect. Speedo off by about 5 mph, but running FORscan with a dongle fixed that.

[@timwindsor03]

Awesome video brother Thanks for sharing. Keep the videos coming. Hope you have an incredible day Much love and RESPECT

[@SmackeysGarage]

Thanks Tim!

[@semlohde1]

I bought a RAM and the dealer has 35 12.5 r20 on 3 other 1500s also. I figured it would be calibrated, it's off 4mph at 40 and 8 mph off at 75. Your gear is so simple- nut the dealer says RAM won't allow them to change it. That's nuts. I really don't care about mph or mpg but it's wrong on the odometer and other sites says it damages the transmission. If this truck can tow 8 to 10,000 pounds, I can not see a tire change doing anything to the transmission. But I flat don't know. Thanks for a good video showing some trucks can be changed.

[@SmackeysGarage]

I have no experience with RAM trucks but check out AlfaOBD or try a different dealership. It's crazy if a dealer tells you they can't do it. There must be some way to fix it. I'd expect a dealer selling a truck to at least have the right speedometer calibration on it!

[@jonathanteal5388]

I had a 5th Gen ram I used edge pulsar to adjust the tire size and also turned the mds off with it. They run about $700 new.

[@musclecarmitch908]

Nice calibration and fix!👍

[@SmackeysGarage]

Thanks Mitch!

[@LTLdrivin]

Define drastic. I went from 225 to 235 65 17

[@SmackeysGarage]

Assuming just the 225 changing to 235, it's only a 1.8% increase in tire size. Not a major change in the speedometer.

[@nealgold8442]

Great video!! Very helpful!! Thanks!!!

[@SmackeysGarage]

Glad it was helpful!

[@trixerbautista6766]

The most convincing video… i am about to buy the obdlink… hopefully my f150 will back to normal.

[@mpatterson212]

I came for the information, I stayed for the information and the fact that when he said forscan it sounded like foreskin and I’m an adult child! Haha Definitely subscribed though! Good info!!

[@SmackeysGarage]

Good to know that is how I get people to subscribe! haha

[@mpatterson212]

@@SmackeysGarage absolutely!! I have a 2013 f150 ecoboost, and always seem to have some of the same issues or problems with it every 6-9 months. So hopefully I can find some tips on here that can help some of my issues!!

[@TAspeed1]

Thank you. Now i just need to find my laptop and obd connector. It's been awhile since I used Forscan

[@SmackeysGarage]

You are welcome! Let me know how it turns out.

[@JesusCabrera-n3m]

What would my value be if i have 33x12.50r20 tires? One website tells me 2617 while the other one says 2631

[@SmackeysGarage]

From the tire calc site it gave me 2631. Between the two numbers it is only a 0.5% difference. Which means at 60, the difference between the two would be 0.3mph which you wouldn't see from the speedometer. I'd start with one and then see how close the speed is comparing it to a GPS.

[@JesusCabrera-n3m]

Thank you sir !

[@JesusCabrera-n3m]

Will a PCM /TCm relearn make a difference or if it’s actually needed

[@Kennyj89]

Do you have to change rhe number back before service or is this a one and done thing? Thank you for the video

[@SmackeysGarage]

No you do not need to change it back. I set mine and haven’t ever looked back. You are welcome!

[@antoonio00]

I have S-Max 2016 (mk2) which is basically fusion/mondeo/galaxy/edge. So, i use 235 /55 R17 tires. Original value was 2098mm and i changed it to 2167 as calculator gave me this number. Originally (thnx for stupid Eu rules real speed must be lower than speed on your clock) at 90kmh real speed (gps) was about 86kmh. So after putting new value i got 82kmh (gps) and 90 on the clock. That means foult was doubled. I restored old values. I noticed there was smth like Speedometer logic or smth. Mine value was Europe and i changed it to North america. And then fault was only 2kmh, 90 on the clock and gps 88kmh. So i went back to tire circum and put not 2167 but -69 (2098-2167) from original value that means 2029. After that i got 90 on the clock and gps 92. Then i made some more test and righ now there is 2050 value which gives me at 90 on the clock and less than 90,5 kmh by gps and 50kmh on the clock and 49,xx on the gps. Soon i gonna put summer tires back and will check and correct those values again. PS have been in US many times and always checked rental car speedos with gps, and always fault have been less than 0,5mph.

[@SmackeysGarage]

Nice work on sorting that out. Definitely takes a few times to figure out what works best and what is close enough!

[@antoonio00]

@@SmackeysGarage hey, one remark, reading error codes PCM gives me error P160A :00-2F Control Module Vechicle Options Reconfiguration Error. So i started to figure out what gives that error and when i changed tire size back to original value (2098) this error was gone. When i put it back to 2050 (better value on speedo) error started to present again. :D Any thoughts?!

[@antoonio00]

@@SmackeysGarage Got fixed that problem. By chance i pressed PCM relearn vehicle and after that this error was gone.

[@travisroy9259]

Mine is still off but not til i reach about 40mph and it gets worse the faster i go. 2011 f150 with 305/45r22. Calculator said 2616 which i tried then i went up a few times all the way to 2700 and gave up

[@SmackeysGarage]

Ah. Don't know how it affects the 11 trucks. I never tried it on mine while I had it. Weird to hear it doesn't change anything. 2700 is only 3% more than 2616. At 40mph, it might make only a 1.2mph change if I did my math right.

[@mikesmerc2006]

I just did this and now I got a wrench light. Unable to clear it, P160A in TCM.

[@SmackeysGarage]

Check this page out. Someone else had a similar issue and was able to remedy it with these steps. forscan.org/forum/viewtopic.php?f=5&t=17408&p=85822#p85822

[@SmackeysGarage]

Let me know if it works. If it does, I will pin the comment.

[@bigworm1384]

any updates? Im about to try this myself. Your post scared me. lol.

[@trixerbautista6766]

i did follow this to reset: reset the PCM- Reset All Adaptations, TCM- Reset All Adaptations, TCM-Clear Transmission Adaptive Tables. DTC codes The wrench went away but the engine alarm still show...

[@trixerbautista6766]

Any luck clearing.?

[@hzardiswastez]

Forgot to mention, I’ve got my speedo at stock and will interpolate the stock mm to the new desired one and see the difference.

[@SmackeysGarage]

That’s a good way to do it

[@Bacnow]

I NEED to do this for my Bronco! However, I don’t own any PCs as my (as well as most of my friends and family’s) home OS is Mac based! I really don’t want to buy a used PC to only use once!😞

[@SmackeysGarage]

Yea I hear you. My main computer is a Mac and it doesn't work. I have an old pc from years ago that I use.

[@cozmicmojo2181]

I had to start the truck while writing the changes. I got errors when the key was just set to the ON position while writing for anyone's reference.

[@SmackeysGarage]

Interesting. Thanks for sharing

[@MrIrbeans]

Has to be done with a PC. Programming option is not available through the app on iPhone or Android. 😢

[@JesusCabrera-n3m]

I changed my number to 2631 ( 33x12.5x20s) my speedometer shows 50 mph but my gps app show around 47-48. How much more should I increase or decrease my number to get it more accurate?

[@markusnachtmann293]

Can u answer me a question? I have a focus St and I have tire size 235/35 19 with 1975mm in bcmii module and also in IPC module but the odometer tells me allways to much (drive with 100km/h odo shows 107 km/h) If I want reduce the shown speed to 102 km/h I will like insert 2005mm. Is it right that I take the changes only in IPC module and not in the bcmii module? If I change IPC and bcmii module, there is no difference (shows also 107km/h on 100km/h speed) Hope you understand, but I am from Germany, thx😊

[@SmackeysGarage]

I understand but I don't know what to tell you. I haven't had to deal with the two separate modules with y truck. You could post in the for scan forums.

[@joaopaulomagri5030]

on my car im going from 205/50r17 to 215/55r17... but even with calculator still 2~3mph (similar issue), any ideas?

[@SmackeysGarage]

At what speed and what is your value you used? I’d change the circumference value until the speed is close.

[@trixerbautista6766]

I just change the tires of my F150 2018 from OEM to 275/65/20. My gas went crazy and I noticed the transmission shifting is a little bit wild from time to time. Would forscan will fix this if the circumference will be calibrated as close as possible? Any magic number for 275/65/20?

[@SmackeysGarage]

It could help. You could also reset the adaptive transmission tables. For a starting point. I'd use 2718 as the circumference of the tire.

[@trixerbautista6766]

Thank you. I would definitely do this. I will let you know the result👏✌️

[@SmackeysGarage]

Sounds good!

[@trixerbautista6766]

Do you have a video how to reset the adaptive transmission table?

[@trixerbautista6766]

i did change the tire size and i have error and shows wrench in my truck every time I keyed in. shows DTCs in TCM:P160A:00-AF error shows DTCs in PCM: U0422:00AF error Can you help me?

[@d.collier_8280]

By doing this, do you think it’ll up the transmission? I noticed after changing my tire size and not correcting it in the computer. The transmission seems to shift differently than it did with the stock size tires

[@SmackeysGarage]

You could reset the adaptive tables on the transmission using Forscan. I don’t believe changing the circumference on the tires it’ll change anything else. I did not notice a difference doing this.

[@d.collier_8280]

@@SmackeysGarage do you mind explaining how to do that? I’m still new to this Forscan stuff.

[@trixerbautista6766]

Hello, Do you have a video how to fix Vin #? ===PCM DTC P0630:00-AF=== Code: P0630 - VIN Not Programmed or Incompatible - ECM/PCM

[@SmackeysGarage]

I have not seen this. Does the As Built file have the VIN correctly inputted? Can you check that.

[@denismanace]

Thank you

[@mexusa]

Will it work with a 2024 Ford Maverick Hybrid?

[@SmackeysGarage]

I would check on the FORScan forums. They will have the most knowledge on what vehicles it is applicable to.

[@hbokhary]

can I use it for gmc sierra 2023

[@SmackeysGarage]

No, it is a Ford/Mazda/Lincoln/Mercury Product.

[@matthewwillingham6128]

If I’m just changing the rim size do I have to do this ?

[@SmackeysGarage]

Only if the overall tire size is changing in diameter

[@dougrobertson3508]

@@SmackeysGarage Your rim has no effect. Only the tire diameter / circumference.

[@Carpermike20]

Super easy to use, but now I’m having the wrench light on. Has anybody dealt with this before?

[@SmackeysGarage]

A few people have seen that in the comments. You might want to see if you can find one. I've seen people be able to clear it by reprogramming it back to stock then reprogramming it back to the updated number. Some have cleared out automatically after driving.

[@Carpermike20]

@@SmackeysGarage I tried that it didn’t work now. I’m kind of freaking out because I have work tomorrow.

[@SmackeysGarage]

Check this site. www.ford-trucks.com/forums/1710048-forscan-tire-size-change-causes-wrench-cel-lights.html

[@RandKingsbyry]

The wrench light has come on now. How do I fix it?

[@SmackeysGarage]

What year truck do you have? I’ve heard a few people having this happen and then it goes away. I’ve sky heard people reprogram it back to stock then try it again and it goes away

[@RandKingsbyry]

2018 f150

[@walkerlilley7092]

I did this just now and I got the wrench light. Any suggestions?

[@SmackeysGarage]

Adjust the number slightly higher or slightly lower. What year is your truck?

[@walkerlilley7092]

@@SmackeysGarage It’s a 2019. I have 275/65/20 tires. And i put in the exact circumference. Would higher or lower be better

[@trixerbautista6766]

After changing the size of the tire and resetting the transmission table I got this error message. Any idea how to get this fix? ===PCM DTC P0630:00-AF=== Code: P0630 - VIN Not Programmed or Incompatible - ECM/PCM Status (-AF): - DTC Present at Time of Request - Malfunction Indicator Lamp is On for this DTC ===PCM DTC U0422:00-2F=== Code: U0422 - Invalid Data Received From Body Control Module Status (-2F): - DTC Present at Time of Request - Malfunction Indicator Lamp is Off for this DTC Module: Powertrain Control Module ===END PCM DTC U0422:00-2F===

[@SmackeysGarage]

What did you input and where for the circumference of the tires?

[@SmackeysGarage]

Some people said after it popped up with the larger tires, they went back to the stock tire size and reprogrammed... then programmed the tires one more time with the larger size and it cleared.

[@trixerbautista6766]

@@SmackeysGarage i follow your video. And my new circ is 2718 mm.

[@trixerbautista6766]

@@SmackeysGarage i will try to again. Hopefully P0630 will go away.

[@SmackeysGarage]

@@trixerbautista6766 Follow up and let me know. It'll be helpful to people who see this pop up.

[@stevengagliardi9006]

I did this but my Speedo is still off. Any ideas on what else to try?

[@SmackeysGarage]

Did the speed change at all in either direction?

[@dougrobertson3508]

Double check your circumstance calculation. This is the distance around the tire. Look up your tire diameter on the manufactures web site (same "size tires" do differ from one model / manufacturer to another). Take the diameter shown and multiply by 3.1416, and then multiply that number by 25.4 to get the circumference In mm. Ex: 35 " tire. is 35 x 3.1416 x 25.4 = 27693 mm. Put that into Forscan. If that doesn't work, you have a different problem in the system. Note: Older worn tires will have a slightly lower circumference which you can compensate for by lowering the number a little.

[@trixerbautista6766]

Hi there, i have question. I add a hub spacer 2inches or 50.8mm . Don i have to add that in tire calculator? For example i have a tire 275/65/r20 would that be 325/65/r20… this changes the circum from 2718 to 2921?

[@SmackeysGarage]

No. That doesn't change the overall circumference of the tire. You would not need to add anything for a 2 inch spacer.

[@trixerbautista6766]

@@SmackeysGarage thank you

[@kevconnors8785]

Does forscan work with Apple MacBook?

[@SmackeysGarage]

People have done it. I have not. It is not officially supported but people have found workarounds. Nothing would be guaranteed to work though it seems.

[@kevconnors8785]

@@SmackeysGarage what PC do you recommend?

[@SmackeysGarage]

@@kevconnors8785 Really any recent PC running windows 11 with a USB-A port. I run it on a 6 year old Surface Book Pro and have no issues with it.

[@DavidWilliams-wj4sc]

But your miles would read less without this calibration. I put 32"s on my 1998 Wrangler and was reading much less speed and miles. THen I put the stock wheels back on when i traded it in for something else :)

[@SmackeysGarage]

Yes you are right that does happen lol.

[@tylerbrannan1710]

Tried but keeps stopping at 17% any ideas?

[@SmackeysGarage]

The programming?

[@tylerbrannan1710]

@@SmackeysGarage yes when I put the tire size in and hit write it starts then gets stuck on 17% and kicks me to the loading screen

[@timshiver7464]

You are assuming GPS speed is accurate. GPS is not. It can vary. Always get your actual tire size from the manufacturer.

[@Grandassets]

its a perceentage, so the faster you go the more its off... I have 285/70/17 and was off about 10% so when the speedo said 60 I was actually doing 66, I havent bothered to change it yet, I just know in my head 64-ish will be 70 LOL

[@JonathanIvy]

F150 forscan hybrid

[@sgkukov2285]

This video seems wrong, more steps are required to actually apple the new tire size information. At least on my F150. Ive run into this and numerous others have.

[@SmackeysGarage]

What did you have to do differently?

[@rmorein000]

he is probably talking about the DTCs in the PCM and TCM after changing tire size in forscan. Have to relearn to fix. I just went through this. I was trying to put in 2631mm but kept getting error. Highest I could get is 2501mm without errors.

[@CrunchDramaNetwork]

Did you say Fore-Skin? Bruh 😅😂

[@SmackeysGarage]

FORScan 😂

[@pierreverdoni]

at 25 seconds I heard fore-skin also !!

[@bigherbthedestroyer2627]

Definitely repeated "skin"! 😅

[@Ch1TownBusta]

I swear he saying 4skin

[@SmackeysGarage]

Guess it’s my accent lol

[@junior88fan64]

Does any1 know what is the number should be when going from stock tire to 35 for 23 f150? Thanks

[@SmackeysGarage]

What’s the full dimensions of the tires? Width/ rim size / height.

[@junior88fan64]

@@SmackeysGarage bfgooodrich 285/75/17 i think circum is 33.8. Thanks

[@SmackeysGarage]

I would start with 2697. The diameter was 33.8.

[@junior88fan64]

@@SmackeysGarage thank you.

[@junior88fan64]

Ok, I just changed n it gave me a warning in dash. "Check brake system" Then I put the old numbers back and again got the same msg. Is this normal? Anything wrong with the brake now? After disconnecting forscan I am not seeing the error anymore...