FORScan help to change tire circumference

[Hande]

So I have several wheel sets for my 2024 RR.
With 35” M/T the speedometer is spot on, but with original 33” A/T it shows 5-6km/h too much. IPC also shows travel distance about 5% too much.

So I wanted to change tire circumference for 33” tires. I made the change in BodyCM and then performed PCM and AWD relearn.
AWD dtc was cleared, but PCM dtc did not clear - just gave me another one U2101 with P160A 🥲

I tried TCM relearn, manually writing new tire circumference into the PCM - nothing helps.

When I insert original 2525 circumference, all dtc’s will clear.

There is something weird… ABS Module says tire size is 315/70-17 but BodyCM only working tire circumference is 2525mm ‍

Please help 🥹

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[mAtTyG04]

I did this yesterday for my 35's. Mine worked out to 2600mm. Do the AWD relearn procedure. Clear DTC's. Then run the "PCM reset all adaptations" service function. Worked fine. Start to finish maybe 10 mins.

 

[Hande]

I did this yesterday for my 35's. Mine worked out to 2600mm. Do the AWD relearn procedure. Clear DTC's. Then run the "PCM reset all adaptations" service function. Worked fine. Start to finish maybe 10 mins.

Thank you! I will try that.

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