[asphaltgambler]

It's odd to me what the manufacturer is getting / profiting from this? No question the 'owner' profits but with all the paper trail that is left from registering a car, emissions testing, State inspections, dealer servicing all someone would have to do...........is look on the interwebs.

Also, it is correct that ever since digital odometer read-outs have been in place, so have there been initially dealer only scan software to modify the reading. It is necessary when the instrument cluster fails and a technician replaces it, then needs to code the correct mileage. Most manufacturers allow only basic administrative levels of mileage transfers where the cluster info is scanned, recorded then that info is uploaded to the replacement cluster.

But there are limited aftermarket scan tools/ software where that process is streamlined and the technician directly inputs the figure manually. Again the assumption is replacing a failed cluster, inputting exact existing mileage.

The cluster is has only display capabilities with a simple memory chip. The DME (ECM) and the trans module ( if automatic) stores the mileage as well. So if the odometer reading was changed, the DME, trans as well as other drive train related modules do not. So connecting a scan tool would immediately reveal this.

However, more common in ever day vehicles the cluster is just swapped out for lower mileage readout from a salvage yard, assuming there is limited paper trail.