is there any system diagnose, kind of scan to check the ecu errors of an S5 na??

 

Yes. http://www.banzai-racing.com/FD&S5_error_codes.htm

 

Thanks rotary , another question, for the codes, the one needs to be flashing is the engine light or there's a kind of led in the ecu that's going to be flashing? i was lookin for a kind of led on the ecu and found nothing, that's why i'm thinking is the check engine light.

 

It is the check engine light on the warning light cluster that flashes the codes.

 

There should be a single pin connector near your battery. Its green! Ground it out and count the flashes on your check engine light. S5 only. S4 you need a tool like banzi to pull codes from the ecu.
Thanks Robert

 

I did that and it doesn't flashes. It just stays on.