SOLVED - Early production 2016 appears to use the 2015 locations (i.e. 726-45-01).

My 2016 is reading 3mph faster than the vehicle is going? Confirmed with another vehicle and gps.
Readings taken at 70 mph.

Tires are properly inflated. On my 2nd set of tires; exact size replacements for OEM.

I guess my odometer is showing more miles than actually traveled. That's a lot with 65k on the clock.

Anyone else have this issue? Is there a way to recalibrate?

 

Often a speedometer is off by a percentage and not by a fix amount like 3 MPH. This means the faster you go the more it is off, so in reality the issue is not as bad as you might think it is. You're reading is off by 4.2% which means at 35 MPH it's off only 1.5 MPH.

 

In and of itself, it's not the worst that could be wrong, but the accumulated miles on the odometer are surely exaggerated. That is a significant issue, so I'd like to resolve it. Hoping there is a way to do it with some parm change in firmware. I can't be the only one with this issue.

 

Is it an issue, per se?

I guess Ford has gone with it this long, so not really.

My ‘03 is a flat 3 MPH over at all times. I figure it’s a way for Ford to shave a few thousand miles off their warranty obligation.*. My truck has the factory issued tire size on it, so it isn’t a matter of someone dropping the smaller sized option on and leaving it.

*I’ve driven a handful of vehicles that have an average MPH info display. Typically, they sit around 30 MPH when I get in them. That’s a 10% error, about 3,000 fewer miles Ford sweats out the 3/36,000 warranty. Beancounters strike again.

 

It can be adjusted in forscan.

 

Get on a freeway and check your odometer against mile markers for a distance of 10-20 miles at least. With modern electronics, there are instances of cars that have speedometers that over-read but odometers that read right on.

If you change wheels/tires to a larger or smaller diameter, I would expect the speedo/odo error to match. But if you are at stock tire size, the factory settings may be different from one another.

 

Yes, that is what I researched and found, but there is another problem...

The Body Control Module settings have 4 selections for tire size. The one that I have 275-65-R18 doesn't have the correct circumference in millimeters (from the factory!). This is why the speedometer is wrong. So, with the forscan, I will have to go into the BCM as-built to get at the pigeonhole for the circumference. In docs I've seen in the forums, that's 726-12-01. When I went to look at that, it is definitely not a tire circumference.

So it got me thinking that my 2016 is an early model that was made in 2015. My rear wiper is different than other 2016s. So, is it possible that the location of tire circumference in my BCM is not 726-12-01? If I look at that for 2015, it is the "use fogs as drl's" setting.

That being the case, there may be another location that holds the circumference.

There are two ways to find out...

One is to change the tire size in the BCM from the selection and see what changes in the BCM as-built. I don't like that idea because a lot of other modules use the circumference (ABS, fuel consumption, etc), and I don't want to set/reset/etc iterate.

The other is to find someone who has a 2016 like mine and who knows the actual location for the circumference in the BCM as-built.
This is a problem because that location doesn't seem to be documented in any of the spreadsheets that I've found. There are 68 locations total.

I'm open to suggestions, but leaving it as-is won't work for me. The difference is large and I already have thousands of miles more on the clock than I actually drove.
I am amazed that there is no TSB on this. It is definitely critical as it affected what was covered and when, and it continues to affect the vehicle even out of warranty and beyond...

 

Solved. Early production 2016 appears to use location 726-45-01. 2nd value on mine is 0x9D0, which is the 2512 for the factory tires.