different versions of mp3 ecu?

[s0n1cm0nk3y]

searching car part I found this:

Elec Cont Unit (ECU), (under right side of dash), 2.0L, MT, MP3, ID FS9N-18-881
Elec Cont Unit (ECU), (under right side of dash), 2.0L, MT, MP3, ID FS9N-18-881B
Elec Cont Unit (ECU), (under right side of dash), 2.0L, MT, MP3, ID FS9N-18-881C

so which one am I looking for? why are there three revisions?

 

[lil_red_wagon]

i would guess that the third revision (c) would be the winner. there is kind of a history of reflashes in mazdas, so that is probably the issue here.