Xanaduit

New to the forum, long time user :-)
My ZJ ECM had been replaced with a wrong part number ECM before I purchased it. The one that was in it was a 409 (which is for 2 wheel drive) After tons of researching I think the part number I need is a 408, 408AB, or 408AC (for 1997 federal emission 5.2 4WD).
Does anyone know how to find out what the original part number was for my build? PS: It's not on the build sheet :-(
THANKS in advance
EDIT: Also what does the AB and AC suffix mean? ie 56041408, 56041408AC, 56041408AB

RocketMouse

First of all... officially welcome to the family and forum....
As for answers to your questions, if you posted your question in the regular forum area I think you'd get a much faster response than in the introductions section.
I don't know the full answer to what you're asking for, but since you're looking for factory stock information, I would start that direction, possibly through a local new car Jeep dealership in your area.
Have you modified yours into 4wd? Curious as to why the ECM would've been replaced with the wrong one before you bought it. When you post in the right section of the forum, any details you can provide will help us assist you more in your quest.

cruiser54

Yes. Welcome.

I'm moving this thread where it will be seen by many more.

wingless

Welcome to the forum.

Here is the applicable parts manual page for your '97 ZJ.

Note that it is very useful / required to have the correct Factory Service Manual (FSM) for your vehicle. The parts manual is also useful.

Xanaduit

Thank you! Yes original 4WD, 5.2, Auto, fed emissions, Limited Edition, but the ECM had REMAN stamped on it. It did function but I purchased this ZJ with a seized motor, swapped the 5.2 with 44RE from my other ZJ same year and specs but Laredo, not Limited. So somehow the previous owner received a 409 (for 2WD) ECM.

dave1123

That would work if it was programmed for the 5.2 4wd. They are all basically the same, but programmed differently.