How to use FORScan to recalibrate speedometer for bigger tires

[Spart]

You'll be able to calibrate your speedometer with the free FORscan software, a portable Windows device, and an appropriate ODB II adapter. The best adapter to get is the ODBLink EX for about $50 on Amazon. Stay away from the chinesium ones.

I have instructions for doing this here: https://www.mustang6g.com/forums/th...ometer-error-no-flash-or-tune-required.67564/

Pay close attention to the need to do a PCM and TCM relearn in order to clear DTC's.

Also, for the 2021+ F150 the address location has changed. Instead of:

726-12-01 xxxx ABCD xxxx

It is now split between two lines:

726-15-01 xxxx xxxx ABxx
726-15-02 CDxx xxx xxxx

The same values from my calculator linked in the Mustang 6G thread will work in the new location.

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[Knickell]

Great information to have. A lot of people don't think about this when the slap new wheels and tires onto their truck. Hopefully there is a YouTube video on how to do it as well up soon.

 

[Pinero]

I’m assuming that forscan is now capable of manipulating as-built data on the new gen? Last I heard, it was not capable yet.

I wonder how long it’ll be until someone compiles a spreadsheet on these.

 

[ford2021]

Dying to know if anyone has actually updated there 21 Speedo

 

[Millionvill3]

Has anyone figured out how to reset the TCM yet?

 

[Coreytime]

Bumping to see if anyone has done this

 

[LUV2FORD]

I upgraded to 35x11.5x20 nitto ridge grapplers and changed the tire size using Forscan. Worked great. Matches GPS. No DTCs.

 

[67SS509]

I upgraded to 35x11.5x20 nitto ridge grapplers and changed the tire size using Forscan. Worked great. Matches GPS. No DTCs.

What do I need to buy and best place to get it? I need to change tire size on my 2021 F150.

 

[Chewza]

What do I need to buy and best place to get it? I need to change tire size on my 2021 F150.

Buy a compatible OBD2 scanner (I have this one https://amzn.to/3mh1Mg2) and the Forscan software, and search the FAQ's on how to use it.

 

[oddlou]

Buy a compatible OBD2 scanner (I have this one https://amzn.to/3mh1Mg2) and the Forscan software, and search the FAQ's on how to use it.

Hi, Matt! Have you actually done this on the '21? I've seen threads on the topic on this forum and the other, but I don't think I've seen anyone say that they have actually done it on the 14th Gen. Has anyone else done it? They looked at me like I had two head when I asked about doing it at my dealership.

 

[Bills]

Yeah my dealership has also said that they cannot update my tire size unless it is a factory option with the truck. (Somewhat full of shit, since others are doing it).

going to be looking into this since I have a lift kit and tires in my garage now.

 

[21lariatspprt]

I called two local dealerships myself and they both said they no longer can adjust on 21 plus, but they could prior on 20 and older. Anyone know if that will change or is forscan the only foreseeable way?

I see hyptertech came out with a solution that requires you literally rip your dash out - no thanks!

 

[flynavy]

Just did it using tire conversion, first two values were the same but I did change second two. This is for 275/70/18… guessing first two values are the 275 which was stock then?

In theory, should my values match a tremor since it used same tire size? Anyone with a tremor wanna confirm for me?

 

[Rapid Red]

Dying to know if anyone has actually updated there 21 Speedo

I have recalibrated mine from 17”std training wheels to 18” 265x65x18 “ overall 2.5” taller.

 

[Rapid Red]

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