Tire Size change

Changing the tire size works the same in all vehicles.

Attention

Make sure your engine is NOT RUNNING

  1. Connect to your vehicle

  2. Open Adaptation

  3. Open Tire & Axle settings.

  4. Set Tire Size:

    • Choose a value from the drop-down list. It represents a tire diameter in inches.

    Note

    If you pick a value that matches your tire size exaclty, your speedometer will be showing a higher reading than your GPS. That’s normal - your factory wheels with factory settings worked the same. Blame the law-makers (At least in the EU). We recommend setting a value that is about 0.5 inch smaller than your actual tire size.

    • If you enabled it in App & Adapter settings, you will have manual input availabe. This however is wheel circumference in mm. Not recommended.

    • With manual input enabled you migth get an error when trying to set a value from a drop-down. In that case, disable manual input.

  5. Disconnect, close the car, let it sit for a few minutes. No ECU reset required.

Notes:

Some vehicles (especially the more “civilian” ones) have a max tire size value they can handle. You can set a higher one, but the ABS module will throw a warning on your dash. Decrease the tire size.

If you have any errors after setting the tire size (including because of the issue above):

  1. Connect to your vehicle

  2. Run Advanced Scan

  3. Clear the codes

  4. Fix the tire size setting

  5. Restart the vehicle and see if the problem is fixed

  6. If not, go to Adaptations, use search to find “ABS Static Init” (preferred) or other ABS Initialization procedure and run it.

  7. Clear the error codes again

  8. Restart your vehicle

If the steps above didn’t solve the problem, then most likely your vehicle is not designed to accept any other value than factory. Go to JScan settings > Trace & Restore Adaptations to either check the history of changes or revert all settings to factory.