Reprogramming computer for bigger tires
Certified Cow Porker
Joined: Sep 2015
Posts: 1,323
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Your odometer reading is inaccurate. Depending on where you live, you can be charged with fraud when you sell it without disclosing the inaccuracy.
If you're determined to correct the tire size inaccuracy you can buy a programmer. My dealer service manager told me that as long as you only used the tire re-sizing feature of the program that there would not be any concern with warranty coverage in the event that there was a warranty service claim in the future.
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Thread Starter
Senior Member
Joined: Nov 2015
Posts: 124
Likes: 16
From: North Texas
That's awesome. I was under the impression dealers could no longer change tire size. There's a few threads on this. It's good to know! Maybe some dealers use aftermarket programmers for tires. Mine doesn't.
Yes, I know about the DTC, it's a com error and only shows up in software. Doesn't cause issues. Every once in a while I get a com error between two modules. It's part of having computers talk to each other.
Yes, I know about the DTC, it's a com error and only shows up in software. Doesn't cause issues. Every once in a while I get a com error between two modules. It's part of having computers talk to each other.
My check engine light came on yesterday. Ran forscan and these codes showed up. Are any of these related to changing the tire size?
Senior Member
Joined: Feb 2017
Posts: 231
Likes: 28
From: Annapolis MD
So, you bought the OBD2 MX @ www.obdlink.com/mxbt/ and downloaded Forscan @ forscan.org/download.htm ?
And that was it? So roughly 75 bucks to change it all? Anyone else do this instead of getting the other programmers etc?
And that was it? So roughly 75 bucks to change it all? Anyone else do this instead of getting the other programmers etc?
NIGHTMARE
Joined: May 2009
Posts: 107
Likes: 15
From: Chicagoland, Illinois
Member
Joined: Dec 2017
Posts: 183
Likes: 42
I used a GPS to verify the discrepancy with my new tires and it was about 3% so at 65 MPH on the speedometer the truck was actually traveling at between 66 and 67 MPH. No discernible difference at 40 MPH or slower speeds. In terms of wear and tear on the vehicle the mileage shown is accurate as you are traveling 3% further with the same engine RPM's and no more stress on the drivetrain than the stock tires. Lifting the truck is another matter and although illegal is something that the LEO's universally ignore in the USA.
