When replacing an ECU, does the ECU part number have to be exactly the same?
Will an ECU from a 1988 Honda Accord EXI 4 door work in a 1988 Honda Accord EXI 2 door coupe. Both have the same engine and auto transmission. I have the part number for the coupe, 37820-PJO-668. The other car is 100 miles away, so I can't get the numbers.

 

I learned this the hard way.... the part numbers MUST be EXACTLY the same for it to work properly. Not knowing this for sure I got an ECU from an 88 LX-i (identical to mine, even down to the color, lol), and sure enough it didn't work. It started up and everything, but as soon as I turned the a/c on it boosted the idle to about 2000 rpm, LOL. I didn't even try anything else cuz I didn't want to fry anything.

If the numbers are the same, go ahead and get it. I know the auto and manual tranny cars had the same ECU, pretty sure coupe and sedan did too. Just make sure the numbers match and you'll be good.