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2021 Speedometer Calibration

brc80

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Just picked my new 2021 2500 and am looking to upgrade from the craptasic factory tire so something a little bigger. Does anyone know if any company is able to correct the speedometer on the 2021's yet.

Thanks
 

jadmt

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Have read two posts recently of people using alphaobd and taser who had dealer issues. Taser had to do with tire size correction and alpha obd was something to do with fog lights i think
 

brc80

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Hmm, I would just like to find a simple way to correct tire size and TPMS. Maybe Ill have to wait for hypertech to figure it out then.
 

jadmt

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Hmm, I would just like to find a simple way to correct tire size and TPMS. Maybe Ill have to wait for hypertech to figure it out then.
Aev snap or dealer
 

pdavey

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I have both the Ram Tazer and AlfaOBD.

I would recommend AlfaODB over the tazer as it has way more usefulness in adding features and making changes and adjustments.

There are hundreds of youtube videos that will walk you through the process of updating tire size.

I just went through the process again as I upgraded to 37 inch tires on my Power Wagon.

Biggest pain in the but with changing tire size is getting the circumference right for the new tires so the speed matches.

Usually takes a few tries to pick the right number.

If you need help let me know.

Sent from my SM-G998U using Tapatalk
 

pdavey

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Yes the 19-21s are all the same. As long as you get the KAOdTECH bypass cable or similar

Suggest the OBDLink MX+ OBD2 module
https://www.amazon.com/dp/B07JFRFJG...abc_7DRE2A1VJ2HR16023A6P?_encoding=UTF8&psc=1

and the AlfaOBD App for Android or iPhone

Sent from my SM-G998U using Tapatalk
 

brc80

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Do i need a bypass cable or anything like that? Sorry new to the Ram world.
 

pdavey

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Yes. See my previous post

Sent from my SM-G998U using Tapatalk
 

Kubguy

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3500 2021 and did the calibration with alpha obd , works good
 

Dave88LX

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Sweet, answers I was looking for.
My 2021 3500 is reading about 5 MPH slow at highway speeds on 37s.
I have an OBDLink MX and AlfaOBD.

Didn't realize I needed a bypass cable, that is good to know.
 

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