Different PCM (Powertrain Control Module) Design on Jeep Grand Cherokee 4.7L V8
There are two types of PCMs (Powertrain Control Module): JTEC and NGC.
JTEC is the older controller, and NGC is the newer controller.
There is an easy way to tell the two apart: an NGC.
PCM has four connectors on it because it integrates the TMC (Transmission Control Module), while the JTEC has three connectors on it because it uses a separate TCM