Changing speedo calibration with Alfaobd

[Smon]

Has anyone changed their tire size with alfobd? I searched and see people talking about it, but no actual confirmation it works or how to do it.

I just bought the pc version to add the trailer brake controller. But after seeing some issues with 4th gens and speedo calibration...I’m afraid to try it.
I swapped to 275/65r20 which is a pretty good jump in size. Normally it’s no big deal to be a little off, but this is significant.
Thanks

 

[RebelWraith]

It works, AlfaOBD has preset tire sizes to choose from. If your tire size is not one of them then you have to put the tire circumference in mm.

After you have edited the tire size use a GPS app or Waze to verify your speedometer at higher speeds. I have 35" tires and had to input the mm equivalent of 33.75" to get my speedo to be accurate from 5-90mph.

 

[Smon]

I’ll try it out. Any idea where to find tire settings?

Had lots of issues using the software with a pc. It would disconnect every 10 seconds. Kept showing COM errors. Using a BAFX BT obd ii reader and a bypass.

I got all 4 trailer brake settings set, but missing the Uconnect setting for trailers. Not sure if it affects actual performance. The dash one shows the gain and brake application using the slider.
Anyone else have connection issues like that?
After getting done I have no backup camera either. Hoping that comes back overnight.

 

[RebelWraith]

I’ll try it out. Any idea where to find tire settings?

Had lots of issues using the software with a pc. It would disconnect every 10 seconds. Kept showing COM errors. Using a BAFX BT obd ii reader and a bypass.

I got all 4 trailer brake settings set, but missing the Uconnect setting for trailers. Not sure if it affects actual performance. The dash one shows the gain and brake application using the slider.
Anyone else have connection issues like that?
After getting done I have no backup camera either. Hoping that comes back overnight.

I'm using an Android so the screens are slightly different, but should help:

Under the option for SELECT CONTROL UNIT choose Body computer MY2016-2017 PowerNet. Next you will need to connect.
Click on ACTIVE DIAGNOSTICS and under SELECT PROCEDURE TO START choose PROGRAM TIRE SIZE.

After that you should have a drop down for preset tire sizes and an input area for specific sizes.

 

[Smon]

I appreciate it! I’ll try it out if everything is back to normal tomorrow.

 

[jwnelson3]

My 5th gen bighorn's digital speedometer does not match the analog by at least one mph. Which one is right? I'm guessing its the digital one. Think the dealer can tweak it?

Sent from my SM-N975U using Tapatalk

 

[Smon]

I haven’t changed the speedo yet, but in case anyone searches this- it took 48 hours for my uconnect to finally show the trailer app under settings.

 

[Grey03svt]

Any luck with the tire size adjustment?

 

[Smon]

Haven't had a chance to do it yet. I will update when I do though.

 

[Grey03svt]

It works, AlfaOBD has preset tire sizes to choose from. If your tire size is not one of them then you have to put the tire circumference in mm.

After you have edited the tire size use a GPS app or Waze to verify your speedometer at higher speeds. I have 35" tires and had to input the mm equivalent of 33.75" to get my speedo to be accurate from 5-90mph.

Did you have to do any changes in alfaobd to the abs system? I seen a vid on an 18 4th gen there needs to be some made

 

[RebelWraith]

Did you have to do any changes in alfaobd to the abs system? I seen a vid on an 18 4th gen there needs to be some made

No sir.

 

[HookedonRam]

Any update on this? I'd like to know as I recently upgraded to BFG 275/65/20s and liked to know if anyone knows the circumference for them. TIA

 

[MrDazana]

Hi guys. small video I made showing the procedure for tire size change in alfaODB.

No errors. No issues. used the the open country 35x12.5x18 tire set. Speedo and GPS are off by .5km. I'm on BFG ko2

cheers