الموضوع: Hacking Digital Odometer

My friend wanted to buy a used car

so he took the car and the owner to the dealer and when they went there the engineer told the owner of the car that someone played with the odometer

the owner of the car face changed in to colors and my friend left and he was lucky he did not buy a car that had some one play with the odometer

the car was Chevrolet optra and I know that this car has digital odometer and I heard that it is hard to dial back the km on the car if the odometer is digital and this method is easy if the odometer was analog

the way the dealer found out this playing was by checking the history car and they found that the owner did the 5,000 service when his car did 3500 km but when he went with my friend so my friend can get a full report the car odometer read 1800 km so the confront the owner with this point

so could some one tell me how is it possible to if it is to play with digital odometer