How to: Recalibrate Speedometer with Forscan for 2021 Bronco

[Bob Blaylock]

Silver lining to not having my Bronco yet: people are coming out with answers to every question I have so damn quickly

When I first started seriously thinking of the Bronco, I came very quickly to see the 2021 as the “beta test” version—the version where all the major bugs will be discovered and corrected, before my 2022 gets built.

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[Bob Blaylock]

I have to chuckle everytime I hear Forscan it seems like a combination of foreskin and Fortran (one of the first computer programming codes) why didn't they just call it FORDSCAN??!!

By the way, the proof that God is real is found in FORTRAN.

Under the implicit typing rule, any variable except those beginning with the letters I through N is REAL by default, unless it is explicitly declared otherwise. And since GOD starts with G, which is not in the range I through N, GOD is REAL.

 

[Bob Blaylock]

@Bronc-Itus unfortunately modern cars don't use the direct from switch to relay wiring like the old cars used to. Now everything is controlled by the computer. all turning on you headlight switch does is sends a command to the BCM which actually turns on the lights. It is the same with the windows and just about every other function. To add fogs using the factory headlight switch would require enabling that option using Forscan, the proper wiring being present in the harness, and the connection being present in the fuse block. Luckily we have the up-fitter switches that we can use.

Something that I have found odd to realize.

In every car that I have ever owned, from a 1969 Falcon up through a 1997 Contour, except for my current 2016 Dodge Dart, there was a direct mechanical connection from the accelerator to the throttle on the engine. When I pushed the accelerator pedal with my foot, I was directly opening the throttle, causing the engine to produce more power.

It felt very odd to realize, with my Dart, that when I push the accelerator, I am not directly opening the throttle; I am merely sending an instruction to the ECM, to express my intent that the engine should produce more power. It is the ECM that then controls the throttle.

I assume that the same will be true on the Bronco, when I get mine.

 

[Bee Bop]

@Bob Blaylock yes Pretty much every car produced now is throttle by wire. I don't know of any that still have the good ole Mechanical linkage anymore. It even looks like the brakes on the Bronco are no longer vacuum assist anymore at least on the 2.7.

 

[b4000]

I have been reading this thread intently and I finally got my Bronco last week. 4 door Outerbanks with standard rims. I quickly ditched the Duellers and put on some 265/70r18's. I then bought the vgate vlinker cable and got Forscan. I went into the Tire field and put in what I calculated to be the correct circumference in MM to my tires? (2646mm), but now I've for a DTC lamp on for the PCM that I can't clear. (P160A:00-2F) I don't have TCM module like in the original how to thread, and when I try to get the PCM to relearn, it says "Service Procedure interrupted". My question is 2 fold.
1) Did my tire size reading actually get changed, with this PCM error?
2) How do I clear this DTC?!

Thanks!

 

[Brichan]

I have been reading this thread intently and I finally got my Bronco last week. 4 door Outerbanks with standard rims. I quickly ditched the Duellers and put on some 265/70r18's. I then bought the vgate vlinker cable and got Forscan. I went into the Tire field and put in what I calculated to be the correct circumference in MM to my tires? (2646mm), but now I've for a DTC lamp on for the PCM that I can't clear. (P160A:00-2F) I don't have TCM module like in the original how to thread, and when I try to get the PCM to relearn, it says "Service Procedure interrupted". My question is 2 fold.
1) Did my tire size reading actually get changed, with this PCM error?
2) How do I clear this DTC?!

Thanks!

See the followup post on the first page that describes what else needs to be done to clear these errors

Just make sure after you change the tire size to force the TCM and PCM to relearn and do the reset of the DTC, then you should not have any error messages:

13. Now we have discrepancy between tire size values known by PCM and TCM and new value stored in BdyCM. So we have P160A DTC in TCM module and P0610 in PCM module:

14. In order to remove the discrepancy, we need to force PCM and TCM to “learn” the new value from the ECC. We can do it using Module Initialization/Relearn vehicle data functions for PCM and TCM module:

Note: some cars may have other modules that require this operation, for example AWD, SOBDMC.

15. After running the Relearn functions, we need to reset the DTCs:

 

[b4000]

Yes.. I've read that post many times. The issue is that when I click to relearn, I get a "Service Procedure interrupted" error and it just stops.

 

[webspoke]

I got the same relearn error for the PCM. AWD module relearned successfully. I took it for a drive and it did change the readings, had to do another change to get it closer. No CEL, but the P160 code is still in the PCM

This is where I am now.
285 K02 - 2525
315 gy mt - 2600

 

[b4000]

I got the same relearn error for the PCM. AWD module relearned successfully. I took it for a drive and it did change the readings, had to do another change to get it closer. No CEL, but the P160 code is still in the PCM

This is where I am now.
285 K02 - 2525
315 gy mt - 2600

Ya. Same thing as me. I haven’t figured out the p160 code in the PCM either or how to turn it off. And because of this I don’t now if the new circumference has actually taken.

 

[webspoke]

Ya. Same thing as me. I haven’t figured out the p160 code in the PCM either or how to turn it off. And because of this I don’t now if the new circumference has actually taken.

The new setting in the bodycm. For tire circumference was saved in mine. My Speedo reading went from 2mph low to 2mph high when I changed it with those steps. Even with the p160 still set on the PCM.
For me 2650 was 2mph high (60 was gps 58)
2600 was 1mph low (60 was gps 60-61). Which is close enough for me.

 

[b4000]

The new setting in the bodycm. For tire circumference was saved in mine. My Speedo reading went from 2mph low to 2mph high when I changed it with those steps. Even with the p160 still set on the PCM.
For me 2650 was 2mph high (60 was gps 58)
2600 was 1mph low (60 was gps 60-61). Which is close enough for me.

I can’t tell if the gps is actually giving me an accurate reading since it’s a sampling and not a real meter. That’s being said. If I’m traveling slower than what my speedometer indicates, I should be setting the circumference lower than what my circumference is, correct? My new circumference is actually 2646mm

 

[Perfect-Beast-2]

Messing with the Bronco brain makes me nervous. I ordered 35's for my Black Diamond. to replace the 32's that are on it now. 90 day wait for the wheels that go with them. The dealer said that it was easy to just change to another size as long as it was an available Bronco size. So, 37's would be more difficult. Something I'm not planning on trying so no issues.

 

[b4000]

Messing with the Bronco brain makes me nervous. I ordered 35's for my Black Diamond. to replace the 32's that are on it now. 90 day wait for the wheels that go with them. The dealer said that it was easy to just change to another size as long as it was an available Bronco size. So, 37's would be more difficult. Something I'm not planning on trying so no issues.

Well. It used to be easy to change them at the dealer. But ford changed their tools and locked the techs out. So now it’s not easy anymore.

 

[Escapod]

I am also getting the error with the PCM relearn, no issue with the AWD relearn.

 

[b4000]

I am also getting the error with the PCM relearn, no issue with the AWD relearn.

Yes. Same as me. No answer.

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