I just took out my stock FD ecu, and it looked weird. See the photos below, thats how it looked, only the gap was simply taped shut.

It has also been added some sort of chip, it seems poorly done since many of the tabs sticking out has just been bent away not to mention the way it's assembled.
The car has also driven just normal, nothing wrong with it. Except that the Mazda error code checker could not get inside the ECU to read any codes, it just errored and shut down.

Can anyone tell me what's been done to it? Or seen anything similar?





The chip:

 

Somebody could have installed something. You can get another used ECU for practically nothing in the for sale section if you're concerned about it.

 

I'm not concerned, I'm replacing it with an Apexi PFC, just wondered what it might be. Since the car is bone stock except CB atm.

 

Been a while since I researched engine part numbers, and I cannot find my notes but I believe N3B7- was the JDM and/or Euro market ECU. That would also explain added board, many JM tuners such as RE-A, FEED added "piggy back" circuits internally. USA was N3A1- for 5 speed and N3A2 or A3 for Auto.

 

Your ECU isn't running the stock code. That chip with the window in it is an EPROM that contains the non-stock code. The little window is in the chip so a UV light can be shone on it to erase the memory on the chip. Who did the mods to it? Dunno.

I would also guess that you have an S7 or S8 car. That ECU is more "modern looking" inside than S6 ECUs that I've seen the guts of. What year is your car?

 

My car is the european model - sold new in Sweden, produced in late 1992.
I have no clue what the previous owner have done to it. The car ran like it should and everything is fine from what I can see. And as mentioned, bone stock and untouched engine bay. Only thing is done when I got it was a Blitz catback.