Hello to everybody! I`m new here and for now i can`t write in other sections.
At first i want to say sorry about that i`m writing here about my problem.I`ve read all similar threads but there isn`t my answer.

I have Mazda RX-8 1,3L 241hp 2004 year.My car was left in my garage for 2 months unlocked in great condition with only 1k miles after engine rebuild.When i got back home i tried to start my mazda. But all that`s happend was sound of clicking from my relays and fast blinking of red car with key inside and when i try to start my radio shuts off when i revers the key to on my radio come back.My first thought was that my battery is dead and i changed the battery with other fully charged battery.But still the same this blinking icon. I tought that maybe is the starter. I`ve tried to start over with pushing but nothing... still blinking.I checked all fuses and relays. My fuel pump is working and i have good battery.My windows,headlights ,central locking ,lights on the dash,radio are working.I have just one key and one key fob that is not working.I decide that maybe is my imobilizer and i went with my car to garage that repair imobilizers and keys and reflash them.Yes but after two days they can`t do anything. They told me that they made 2 new keycoded keys and my mazda don`t recognize them or my problem is other kind of..Is there anybody with the same problem and who can help me. Thank you. My other opportunity is mazda but there is too expensive. And.. how my mazda can went in that anti thief mode...alone??

 

If you've satisfactorily ruled out your battery, this problem is entirely new to me.
It's possible that two months of inactivity in cold temps will discharge the battery sufficiently to have inadequate juice to power the starter, but you mentioned that you've tried it with a fresh battery...

That being the case, the blinking key icon would have me try a new battery for the key before checking other electrical issues.

 

I've changed bundle of starting components- pcm,imobilizer,key,antenna from working car and nothing,still the same fast blinking icon.And no communication error.Maybe lost communication between ecu and imobilizer? Or problem in the dash solderings?The imobilizer is tested with oscilloscope and is with perfect graph.

 

fast blinking icon means it can't read(or mismatch) the key

in this case, you NEED dealership to code the key again for you. there is no other way around it.

 

Yeah,you are right and thats the reason why we changed all starting bundle(pcm,imobilizer,antenna and key) from working car,just to eliminate this option but nothing different.When we read the ECU key ID's was still there and when i read the key is with the same ID like ECU expect... This will be hard..We changed the keycode and the code in ecu but still nothing.RKE mistakes for 'no communication and imobilizer problem'.I'm still in reading about more reasons for that...just 2 months alone and that happends..

 

Two days in mazda..start cranking,after 1 hour the same story.My mazda delete it keys Very,very strange situation )