I recently linked Click and Clack’s answer to why the data in digital odometers isn’t lost when a car’s battery is removed to my blog http://blo…-mill-man/ (See “Odometer Update.”) Well, the good folks at Ross-Tech, makers of diagnostic software for VWs and Audi, weighed in and say that Tom and Ray got it wrong. So, guys, is Ross-Tech right?
I know of no cars that store the odometer reading magnetically. The ones that I know of (Fords) use FLASH memory, which is non-volatile (meaning that power is not required to retain the memory.)
The Ross-Tech guys have it right. You could, kinda-sorta, call EEPROM a magnetic storage, but it’s not really. Magnetic storage implies a tape or disk or, God help us, ferromagnetic beads, but not solid state electronics which is what EEPROM is.