Setting arbitrary tire sizes for speedometer calibration

[Dordogne]

Has anyone successfully completed a tire size change for 2011-2014 F150 using this method?

To my knowledge - no. The 2014 and earlier trucks are on the last generation of as-built as I mentioned, and this doesn't seem to work in any Ford vehicle that isn't on the current generation of as-built.

Side note: is there a way of referring to the different generations of as=built that I'm not aware of?

HOWEVER, the FORScan devs are working on adding a PCM module initialization procedure to relearn vehicle data, and this apparently reads the BCM data for tire size into the PCM on the newer vehicles. This has been used with some success to eliminate the DTC you get from this mod in 2015+ F150's. I do wonder if something like this is what's needed to make the mod work in earlier gen as-built vehicles. See the tail end of this thread: https://www.f150forum.com/f31/correct-y ... 73/index6/

[akcooper9]

I downloaded the AS BUILT from the truck and online. Here is a screen shot of the current state of the ABS module in my 03 7.3 PSD. Note, the tires have been adjust by the FORD tool a few years back so I wonder if that is what is causing the 'error' in the two lines that say Tire Size. Any thoughts or suggestions on what to do next? I would really like to figure this out but need some help if possible. Thanks!

[jdstratton]

I have a 2014 Super Duty.... None of this is working. As soon as a plug in a hex value out of range it throws codes. I also have tried the PCM re-learn, the TCM re-learn does not work, errors out and quits.

[bockhold]

I have a 2017 f150 with 20s. Changed to 33 12.50 20 which the metric is 275 60 20, used the calc on here to get the hex value. Changed it and the 3rd block changed also after the save and reboot. So i get the common service wrench and the same dtc of p160a on the pcm and tcm. Can not clear it at all. Haven't reverted back to the previous values yet but was wondering if there was a fix yet or the values are incorrect or need to force the truck to relearn.

[xlnet]

Bump

I was just about to try this tire size change on my 2015 F150 to correct my speedo. Has there been any update on getting rid of the code it throws after the change is made in the BCM? I checked earlier posts that led to the F150 forums but there was no answer. Also, is having the PCM and TCM codes present going to cause an issue with anything? Or can the vehicle operator just ignor the light and know that everything is fine?

Any help is appreciated,

Thanks

[bockhold]

I reverted to the stock setting. Oddly enough the stock updated some how and was spot on with the gps. Wrench went away too.

[SteveInWV]

I have a 2013 F150 and cannot get this to do anything with my truck. I just had 295/60 R20 Nitto Ridge Grapplers installed on my OEM 20" rims. I've tried changing the pre-canned settings, and a customer setting using the calculator, and no matter what I do, my speedometer is 3 MPH slow.
Any thoughts?
If it can be done with a tuner, which I have read can be done, I have to believe that it can be done with Forscan.

[CombatDork]

I have done it on my 2013 F150. Though the field is different. It is in the BCM still though. If you use the Factory Tire size settings to find the exact field you should then be able to use the rest of this thread's data to enter a custom Tire size.

However, I have had limited luck with Ford Cars and Trucks that are equipped with Advance Track. Something gets thrown off sometimes and I haven't tracked it down yet.

[Weekend]

I have done it on my 2013 F150. Though the field is different. It is in the BCM still though. If you use the Factory Tire size settings to find the exact field you should then be able to use the rest of this thread's data to enter a custom Tire size.

However, I have had limited luck with Ford Cars and Trucks that are equipped with Advance Track. Something gets thrown off sometimes and I haven't tracked it down yet.

Please, describe, how to change tire size for F-150 2013? I'm try to change, but car ignore setted values and up error for new values;(

[CombatDork]

Ok.

1. Launch Forscan and connect to truck while running.
2. Click on the Chip icon, aka the "Configuration and Programming" tab.
3. Click on "BdyCM (AS BUILT format)"
4. Click on the Play icon, aka the "Run Service Procedure" button, on the bottom.
5. Read pop-up window and hit "Ok"
6. Click on the "Safe All" button at the bottom and save the stock data.
7. Click on the stop button, aka "Stop Service Procedure" button.
8. Click on the "Configuration and Programming" tab up top.
9. Click on the "BdyCM" line
10. Click on the Play icon, aka the "Run Service Procedure" button, on the bottom.
11. Click on the "Tire Size" line.
12. Click on the "Edit Selected" button near the bottom left.
13. Select other tire size and click ok.
14. Click on the stop button, aka "Stop Service Procedure" button

Repeat steps 1 through 5 and compare line by line and you should be able to find what the service procedure changed. That will be the tire size field.