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View Full Version : C0279 code after speedo/tire calc.



Goobs
July 15th, 2025, 04:25 PM
I finally got around to correcting my speedo for tire size and the shift points, but now im getting the traction control light on constantly and the c0279 code. I can flash the previous tune and it goes away, so I know it is because of this.
The speedo is about 2mph high, based off my phone GPS speedo. But I dont think that would cause the TC light & code to be thrown.

Any help is appreciated.

nonnieselman
July 21st, 2025, 01:56 AM
What vehicle you working with?
Sounds like a ABS issue

Goobs
July 21st, 2025, 04:04 AM
2003 gmc yukon xl.
I put the previous tune back in it because I got tired of the cel. No issues or codes currently.

I haven't tried but I was using the provided table to change all the associated parameters too. I may try just changing the speedo and see what happens. Then try changing the shift times

nonnieselman
July 21st, 2025, 12:23 PM
Post both your tunes.