2016 F150 Can't correct speedo

[DanTucker]

I have a 2016 F150 5.4 that the customer went to 31.9" tires. I am completely lost on how to correct the speedometer. I have tried changing the Gear Ratio and Tire Size with no luck. Here are a few of my questions. What is Learn From BCM vrs Calibration on the gear ratio and final drive? Next what is the Driven Tire Circ, Max Tire Circ, and Min Tire Circ? Same thing on Final drive what is Max Ratio and Min ratio? I have changed these setting all over the place and it doesn't seem to change the speedometer at all. What am I doing wrong?

[DanTucker]

OK I got it. I used the VCM Scanner part of HP Tuners and clicked the green button and selected Special Functions, Speedo Calibration Change and entered the tire rev per mile and BOOM it corrected it! I would like to say that this is CRAZY hard to find and I wasted a lot of time. I sort of feel like HP Tuners owes me one.

Dan Tucker

[96gt4.6]

Covered in post #20 on this thread. My search string was "Ford Speedometer Correction"

https://forum.hptuners.com/showthrea...ter+correction

[dfost33]

ive tried this on my 2016 and scanner doesnt have a option anywhere for tire size