Just replaced my ECM from a 1991 Jeep Cherokee Laredo 4.0L into MY 1994 Jeep Cherokee Sport 4.0L. Everything I have found on this site, and other sources, say that the modules are compatible.

Now cannot get started due to anti-theft immobilizer.... I have no idea how to begin to troubleshoot this. I only have the 1 original key, there is no chip on my key... Ive locked and unlocked both doors (opened and shut). Locked/unlocked tailgate also opened and shut several times.... opened and shut hood several times... is there a way around this?

HELP!

I have a trouble shooting chart here but I do not think I can get it to you,it is quite a long process. You can try to turn your key to acc 3 times and then leave it there,this starts the diagnostic process. your horn will sound twice or should.
The only other thing I can think of is,do you have an owners manual that may help or get a repair manual.

Thanks Mixed 89... We ended up finding the exact replacement for my computer from another 94 and everything ended up working out.

Know anyone interested in an ECM from a 1991 Jeep Cherokee Laredo 4.0L PN# 56005 707?

yea,i learned something to.

Just thought I would give an update on something new I learned with the ECM. A friend of mine also had a problem with his ECM, we couldnt use my spare ECM since it had the anti-theft... went to the junkyard and pulled one from a 93 Manual Cherokee, and placed it in his 95 automatic cherokee and it worked fine... for ****s and giggle we swapped the one from my 94, and it worked as well... although his "broken" ecm worked in mine as well... so we think he had a loose connection for the ecm, and all the swapping fixed it... Just thought I would say that like we talked about before, that the ECM's are interchangeable, just have to match the anti-theft...