stevieb_wv

As I posted above, "I also tried using the speedometer difference portion of the calculator with 70 set as the speedometer and 73 as the GPS value, but still no change."

It's like it doesn't matter what is in the tire size section. I'm not convinced that it actually works.

jdunk54nl

I am not exactly sure what you are doing or why it isn't working. I, as well as others, have been able to get this to work or at least the preset tires to work and change the speedo even if it is just a slight change with the stock presets.

At this point, I would attempt to go back to stock on your BCM and then try re-adjusting from there only changing your tire size if you did other modifications. Then make your other changes one at a time to see if it messes up your speedo again.

To me it sounds like the change isn't actually sticking in the BCM. You have went back and verified that what you changed was still the value in that line correct?

jdunk54nl

Just had a thought.

You might try doing a BCM reset via forscan. Maybe your BCM is just "stuck" from making changes and needs to be reset. It is a computer after all.

stevieb_wv

The only other BCM mod I've done is to disable Hyperflash from installing LEDs and Bambi Mod. I'll return it all to normal, reset, then try the tires first and see what happens.
Appreciate the help.

stevieb_wv

OK, here is what I've discovered after about 2 hours of testing.
First I removed all BCM customization, set to stock tires, and did a BCM reset. I changed the tire size, no speedo change. I tried a PCM reset, no change.
I added my customization back one at a time. I repeated with every tire size listed in Forscan, plus my custom size.
The main thing that I discovered is that unless I have my original tire size programmed into the BCM, it throws a DTC error U0422 configuration error in the PCM. I suspect that the PCM is ignoring the change explaining why the speedometer doesn't change regardless of what I do.
I tried a BCM reset and a PCM reset, but the DTC error remained.
I'm thinking that for some reason, the PCM needs to be programmed with the change as well, or it's not going to work.
I welcome any input.

lutter5-0

I tried to program mine to Raptor size at 3 dealerships, it throws a PCM code (IIRC, and wasn't a CEL), and doesn't change the speedo at all. Ended up buying a Edge CS2 refurb on eBay for like $250.

jdunk54nl

You have the bad code

https://www.f150forum.com/f118/forsc...2/#post5514682

stevieb_wv

Well I guess that explains it. Probbly why it worked on yours but not on mine. 2013 vs 2014.
I supposed I'll be saving my pennies for a tuner.
Thanks for all of the help.

Spiky

Who else has gotten this to work? I haven't seen a single one, everyone seems to give up and use a tuner. And pretty much all the stock presets are the exact same circumference tire, so those really aren't going to do anything, anyway.

stevieb_wv

Must be a 2013 thing since it was reported that it works on a 2014. I picked up a Hypertech Speed Calibrator and it works. I'm still fine tuning it, but it is definitely making changes.