I bought Diacoms Marine Software (eBay rocks) to see my engine hours and to have a handy tool at my disposal if I ever needed it. One question I need to find is how to identify which type of MEFI I have. I Googled the number I found on my ECM (D1AF) with no help. That was the only number visible. Maybe I need to remove the module to see if a number is hiding on the mounting side?

My boat is a 2001 Powerquest 280 Silencer with 502 MAG/MPI power.

Once you connect up your Diacom software, the MEFI type is displayed in the dialog box in the lower left margin of the screen.

It should be a MEFI 3 . I have 2000 502's and they have MEFI 3 comps.

502 Mags used a Mefi 3 after 1998 1/2. Before that they used a Mefi 1. There is a number on the back of the ecm. It is an 8 digit number and yours will end in 999 or 009 if it is a Mefi 3.
Eddie