Mazda 3 2004r 1.6 P0602 error HELP

[Fliper85]

Hello. Needs help with a car Mazda 3 1.6. The ECU fault P0602, the speedometer does not work .... someone help ??

[YoungDan]

Hello, I have seen this fault a few times. this fault has been cured by software update at dealer. BUT one of them required a new ECU.

Fault code is sometimes caused when battery has been flat and then seen a power spike when a booster pack has been connected, this can sometimes cause the software within the chip to become corrupt.

Common on modern cars.

This has been the issue in my cases. im not saying in any way that this is definately your issue as i have not seen the vehicle.