Diablosport Forums

I just installed 5.38 gears and 35" tires on my 05 Jeep Wrangler, so I am trying to correct the speedometer.

Anytime I attempt to adjust parameters in the tune file to change the tire size/gear ratio, it says "Failed to update size" or "Failed to update axle ratio".
The same thing occurs when I attempt a quick tune. What am I doing wrong?

The other issue, is that the gear ratio that I installed in my Jeep (5.38) is not an option in the tool. The largest tire size is 35", which works. But what if I move up to a size >35"?

Is it possible to update my current tune file with these parameters?

Transfer case: NP241
Gear Ratio 5.38
Tire size: 35", but the measured height of the tires are around 34.5" when the tires are on the ground.

Quick Adjust has a quirk where sometimes the adjustment goes into place on the intended module, but the key cycle does't register, causing the device to give the failure message. If it asks for a key off/on before displaying the failure message, the calibration has actually loaded. You can also confirm this by opening Quick Adjust and checking the value displayed. If it's what you entered previously, then the adjustment is indeed in place.

If it still seems that the adjustment isn't working, we can try loaning a Flashcal from our sister company Superchips. Just call 561-908-0040 and we can make the arrangements.