FORScan Speedo Calibration for larger tires

[RedlandRanger]

I thought I had seen this posted before, but I can't find it. My brother bought a new Ranger and has oversized tires on it but his speedo is off. I was trying to help him fix that. I found some postings on the FORScan forums but they all sound pretty involved.

Has anyone here used FORScan to calibrate the speedo for larger tires? Any hints or tips would be appreciated.

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[Willcuts93]

https://ohptools.com/blogs/news/how...ire-calculator-and-configure-it-using-forscan
I strongly suggest reverting it back to factory if any computer reprogramming needs to be done at a dealer, it sets a check engine lamp if it's updated and is extremely hard to fix.
I have 285/70r17 tires and can confirm this works perfectly if done properly.

 

[Willcuts93]

https://docs.google.com/spreadsheet...z1il2R9K9anNAUSBAeUNKmgYwKFhRtqt1ZePrrw#gid=0
Here is a better link directly to the calculator.

 

[RedlandRanger]

https://docs.google.com/spreadsheet...z1il2R9K9anNAUSBAeUNKmgYwKFhRtqt1ZePrrw#gid=0
Here is a better link directly to the calculator.

FYI, this is the link that worked for me (the one above didn't allow me to enter/edit data):

https://docs.google.com/spreadsheets/d/1mWnuQZlDTUGjKjmJje1QJIR8Z2c7Kf8KBZxKnw_8EqU

 

[sbacpo]

Has anyone done this on their truck and verified it worked?

 

[sbacpo]

FYI, this is the link that worked for me (the one above didn't allow me to enter/edit data):

https://docs.google.com/spreadsheets/d/1mWnuQZlDTUGjKjmJje1QJIR8Z2c7Kf8KBZxKnw_8EqU

I've verified that this does work (Steps 1 and 2 anyway). Someone should add it to the Forscan Wiki.

 

[RedlandRanger]

I tried to help my brother do this calibration today and it appears to have worked (he is going to tell me for sure when he gets home how it compared to his GPS), but once I changed the 726-12-01 value to the "new" value, the PCM threw a U0422 code. It doesn't trigger a check engine light, but I was unable to clear it. In googling, I found quite a few instances where people had exactly the same issue. Doing the PCM Relearn function wouldn't clear it either. It doesn't seem to cause any problems, but it would be nice if we could figure out what was causing that code.

Edit: On his drive home, he said the GPS said 69 or 70 MPH and the speedo said 69. The Odometer was very close as well. 28.8 on the odometer and 29 (rounded) on the GPS. So, other than the PCM code, it seems to be working as expected. The PCM code doesn't seem to be hurting anything and based on the postings I saw, some people just left it that way.

 

[petulantskeptic]

This is frustrating. I upsized my tires only slightly (3.6%) but I'd still like my speedometer and odometer to be accurate so I fooled around with it in ForScan but there's more work that needs to be done I think.

When I change 726-12-01 from its default xxxx 0934 xxxx (my stock tires were 265/60R18) to xxxx 0984 xxxx (new tires are 265/65R18) I get a persistent PCM DTC (U0422:00-2F) indicating "Invalid Data Received from Body Control Module"

It doesn't throw a CEL but it does make me wary of how the BCM change affects adaptive cruise control or other modules like ABS (though they're not reporting errors). There also seems to be an intermittent PSCM DTC (U0140:00-08) indicating "Lost Communication with Body ControL Module" that I don't understand since it only pops up every once in awhile.

I've tried it set to everything between 0984 and 0995 (since various decimal to hex calculators and methods give result in slightly different millimeter circumference values to convert) there ought to be a Ford blessed value in there somewhere since a 265/65R18 is the same outer diameter as the 265/70R17 Ford is saying is acceptable in the Fox kit press stuff. I guess I'll try a HyperTech and see if it works.

 

[FULLSCALE]

This is frustrating. I upsized my tires only slightly (3.6%) but I'd still like my speedometer and odometer to be accurate so I fooled around with it in ForScan but there's more work that needs to be done I think.

When I change 726-12-01 from its default xxxx 0934 xxxx (my stock tires were 265/60R18) to xxxx 0984 xxxx (new tires are 265/65R18) I get a persistent PCM DTC (U0422:00-2F) indicating "Invalid Data Received from Body Control Module"

It doesn't throw a CEL but it does make me wary of how the BCM change affects adaptive cruise control or other modules like ABS (though they're not reporting errors). There also seems to be an intermittent PSCM DTC (U0140:00-08) indicating "Lost Communication with Body ControL Module" that I don't understand since it only pops up every once in awhile.

I've tried it set to everything between 0984 and 0995 (since various decimal to hex calculators and methods give result in slightly different millimeter circumference values to convert) there ought to be a Ford blessed value in there somewhere since a 265/65R18 is the same outer diameter as the 265/70R17 Ford is saying is acceptable in the Fox kit press stuff. I guess I'll try a HyperTech and see if it works.

Thanks for your input. I’m about to put the same diameter of tire on but maybe now I’ll hold off on adjusting until someone gets this sorted out!

 

[j0shm1lls]

This is frustrating. I upsized my tires only slightly (3.6%) but I'd still like my speedometer and odometer to be accurate so I fooled around with it in ForScan but there's more work that needs to be done I think.

When I change 726-12-01 from its default xxxx 0934 xxxx (my stock tires were 265/60R18) to xxxx 0984 xxxx (new tires are 265/65R18) I get a persistent PCM DTC (U0422:00-2F) indicating "Invalid Data Received from Body Control Module"

It doesn't throw a CEL but it does make me wary of how the BCM change affects adaptive cruise control or other modules like ABS (though they're not reporting errors). There also seems to be an intermittent PSCM DTC (U0140:00-08) indicating "Lost Communication with Body ControL Module" that I don't understand since it only pops up every once in awhile.

I've tried it set to everything between 0984 and 0995 (since various decimal to hex calculators and methods give result in slightly different millimeter circumference values to convert) there ought to be a Ford blessed value in there somewhere since a 265/65R18 is the same outer diameter as the 265/70R17 Ford is saying is acceptable in the Fox kit press stuff. I guess I'll try a HyperTech and see if it works.

I haven't had time to install the newest Beta Forscan nor adjust my tire size, but from what I've read at least on the F150s, you have to do a PCM Relearn and maybe a TCM relearn (if the ranger has a TCM module) after updating your tire size. Would you mind reconnecting to your truck with Forscan and checking if it has these two options?

 

[petulantskeptic]

There is no TCM module on Rangers.

I tried the PCM relearn multiple times at various different 726-12-01 values. It never cleared the error. On F150s changing 726-12-01 causes a different error code than on Rangers. On F150s it throws a P160A, whereas I consistently get U0422.

 

[RedlandRanger]

There is no TCM module on Rangers.

I tried the PCM relearn multiple times at various different 726-12-01 values. It never cleared the error. On F150s changing 726-12-01 causes a different error code than on Rangers. On F150s it throws a P160A, whereas I consistently get U0422.

That sounds exactly like what happened with my brothers truck. U0422 sounds familiar. And I did do the PCM relearn multiple times but it didn't make any difference. I cleared the code and as soon as you restarted the truck it came back immediately.

 

[Mellow]

Has anyone successfully done this yet on the Ranger? I'd like to adjust mine to the 265/70 17 value.. xxxx-0987-xxxx but it some codes are going to be thrown then I'm not crazy about that... obviously.

 

[sbacpo]

Has anyone successfully done this yet on the Ranger? I'd like to adjust mine to the 265/70 17 value.. xxxx-0987-xxxx but it some codes are going to be thrown then I'm not crazy about that... obviously.

I have. Changed to the 285-70/17 setting. No codes thrown.

 

[Mellow]

I have. Changed to the 285-70/17 setting. No codes thrown.

Thanks!

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