Yes, recording mileage is ceased in all control units (ECUs) while the module is activated. To have a more in-depth understanding, here is how Mileage Stopper works: As you drive the car, the ABS constantly receives impulses from the wheel sensors. This information is sent from the ABS to the speedometer via the Can Bus system. The speedometer (instrument cluster) receives this message and starts to calculate a distance traveled based on this data. Speedometer sends this data to all the control units including CAS, BDC, TCU, and BCM. After installing and turning on the Odometer Stopper, the speedometer cannot calculate the mileage anymore. Hence, the remaining control units are also unable to record this data.