I purchased a 2000 Grand Cherokee w/ a blown motor 4.7L V8 [N]. 149000 miles replaced the motor with a 2000 G/C that has approx 114000 miles 4.7L V8 [N] everything went together very well BUT when I started the motor the engine light came on and eror code is 601. Question can I replace the PCM /ECM with one from another 2000 G/C or?
Should be able to. GM didn't start that programming nonsense until a few 2002 models. Ford and Chrysler usually don't copy GM's customer-unfriendly ideas until many years later. The Chrysler Engine Computers in that time period can be flashed with updated software but that is only to address emissions-related problems or driveability problems that become known years later, not so you have to spend money at the dealership. They do that so they, (and you) don't have to replace computers like we did in the '80s for those problems.