The LM block is written (and, more precisely, duplicates from the dashboard) the car mileage data. If the data in the LM block does not match the data in the instrument panel (the permissible error is 100-300 km depending on the car), an "Internal LM in LM unit failure" error is recorded and the data in the LM run is no longer added. If this error occurs, it is almost 100% probability that the car has been mileage. The fault should be on its own after the mileage rates in the dashboard "catch up" in the LM clause.