2 engine computers

[metalmoto]

I once owned a early 2002 Liberty. After it dropped a valve and ruined the engine. I bought a 2004 and started swapping over all the new parts I put into my 02 before the engine was destroyed.

Anyway, does anyone know what year they changed the ECM/PCM from a 2 piece unit into a 1 piece unit?

Also, noticed the exhaust system was changed on the 04.
As I remember, I was able to swap the muffler and tailpipe, but the cat converter was changed.

 

[benibiker63]

I have an 02 and I believe it's the next year that they went to one computer. I had to replace the transmission controller and it is separate from the engine computer. 03 and on have them combined. When I was ordering the controller, they kept sending me the combined one for a 03 and above which didn't work. The transmission controller is on the left side against the engine wall on the 02.

 

[slingworks]

It's not really related to your questions 100%, but I'm going to add experience from my advice. If you jeep overheated and caused a problem with the valve or valve seat, I'm suggest replacing the electric fan AND installing a mechanical clutch/fan on it if you don't have one already. If you don't have a Clutch fan type shroud on your jeep you can buy one w/ the electric fan as a unit.

It seems that Liberties are prone to overheating mainly because of junk electric cooling fans. That combination along with a new thermostat would surely prevent any such failure again.

I do remember the 2002's did have some issues with the design causing valve failure, but overheating is an issue for all of them.