Ecu codes?

[240sxHitman]

I was wondering ive been reading sum posts with ppl saying the ecu is giving me this code and that code, how excatly to you read or tell which code it is?

[dumbstroke8]

don't know how to do it for newer models, but on my '89 i unscrew the passenger side kick panel and remove three screws on the panel below the door. then, the ecu can be removed by taking out the bolt holding it in place. then, without unplugging it, just turn the unit around on the vertical axis so you can see the back. use a flathead screw driver and turn the screw half a turn. the two lamps (red and green) will flash. when they flash three times turn it back to where it was originally, then your codes will come up. the number of red flashes is the first number and the number of green flashes is the second. again this is for the 89-90, but its probably similar for later models