Problem: Can't Program Key Fob; On step #6 of instructions for programming key fob, the door locks do not cycle on, then off, to indicate readiness for programming. However, if the key is removed or the door is closed, the locks cycle on/off twice.
SOLVED: Solution for Step #6 Problem During Programming Mazda 3 Key Fob on a 2004 Mazda 3
I was able to solve this problem simply by disconnecting the battery (not sure if it matters, but I left it disconnected for 15 minutes), then repeating the programming instructions. Note: Be sure to write down your radio stations before disconnecting; you will need to re-program them.
For what it's worth, I was able to program a key fob with a DIFFERENT FCC ID than the original key fob. In my case, the original was KPU41846 and the new one (from ebay) was KPU41794. (If anyone cares, I bought it
https://www.ebay.com (commissions earned)...be warned that the auction lists the FCC ID KPU41846, but I actually received KPU41794 [doesn't matter, still works]).
What DID NOT WORK was
Seryous' advice about going to some sort of diagnostic security mode by cycling the key on/off for 4 times instead of 3.