I don't have any experience here, but from what I have read, you would either need ForScan or your dealer could make the adjustments.Tentatively planning on a leveling kit and 34s or 35s on my new Limited (seems it fits based on recent reviews). How easy will it be to calibrate the speedometer and other pertinent sensors for the new geometry and height?
All the dealers will tell you that right now. They don’t have the software yet.If you have a dealer that is telling you that the speedometer can’t be recalibrated, find a new dealer.
Ford’s design teams have been making the wheel wells/arches increasingly larger with each new generation to keep in line with the trend of ever larger tires and wheels. The only reason why you can’t order an F150 stock with 35” and 37” tires is CAFE standards and NHTSA tests. Otherwise, Ford would have loved to be offering 4.30 gears and the new gas 7.3 liter engine on their best selling vehicle, MPG be damned.
The idea that Ford won’t allow speedo/odometer calibration is ludicrous. It just shows that some dealers think they can say anything.
Exactly. I bought mine from the dealer and their customs shop did the lift and tires/wheels. They did the Speedo recalibration before giving it back. No way a dealer hands you a truck they did the work on that is off. They would get killed for it, and also, your truck would end up showing approximately 10% miles less then you actually drove which means your warranties and other things last longer which they would get killed by their management for lol.My two cents! I’m pretty sure at about 99.99% sure either the dealership can change the tire size or they have a programmer that will change it that isn’t available to the public. I say that because it would be crazy and illegal to sell a brande new ( never registered/titled) vehicle from the dealership with the speedometer off. A lot of dealership sale built trucks with lifts and larger wheels/tires so I think it’s all in who you know or how well you know at/the dealership..
Where do i find those codes? I went in and edited the mm for my 285x65x20 my speedo is now 3-4 mph faster than gps. I downloaded the google sheet that allows you to plug in the values to change the numbers in that strand but cant find any of those codes, Any help would be great. ThanksYou'll be able to calibrate it 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.
I think that’s where I originally changed it and got the circumference from forscan tire calculator. Is their something I’m missing?It is actually pretty easy to do and you don’t need the codes or the tables. From the BCM module (not from the as-built menu), there is a selection for “tire circumference” that you can change and relearn. I changed mine to what the tire MFR said was the circumference and did a test ride against my gps. Had to do a little math but second adjustment was perfect. It is really simple, the most time is spent saving all the original settings just in case anything were to happen.
Doesn’t sound like you are missing anything. All the info I had before I started was based on the tables and changing digits of that code, it wasn’t needed and changing the circumference was very easy.I think that’s where I originally changed it and got the circumference from forscan tire calculator. Is their something I’m missing?
@Al or Bill, just looking to know if this calibration worked out well after a few weeks of driving? Also, did either one of you have your truck equipped with Active Assist 2.0 prep (aka BlueCruise prep) package? I'm hearing from local tuner shops they are concerned or had issue with messing with any speedo settings on a truck with this package. thanks for any help/updates!Thanks for replying bill. Yeah I basically just went back last night and rather than using the number that the calculator and wheel MFG kicked out changed tire size to 34” from 34.6 did the math and kept dropping down the circumference until I got goose to gps. I’m now within 1-2mph @70 mph of what gps is reading and probably close enough.