Modern cars have electronic dashboards with digital odometer displays. The car manufacturers use these because they are cheaper to produce than a mechanical dashboard and easier to fit into the car, as there is no mechanical speedometer cable. This new technology has its own problems though, electrical pulses in the cars wiring can cause the dashboard data, which is stored internally on an EEPROM (Electrically Erasable Programmable Read Only Memory), to become corrupted.

This corruption could happen for a number of reasons:

1. The vehicle battery was discharged and the vehicle had been jump-started
2. The dashboard may develop an electrical fault
3. The dashboard may be damaged in a collision or through vandalism.
4. Where a replacement Cluster has been purchased

In these examples, the corruption of the information held in the EEPROM may mean that the mileage displayed on the Speedo is now incorrect.