1996 model year Chrysler product  should be OBD2 compliant and have the typical 16pin OBD 2 connector beneath dash, and scan tool communication for just Engine control and TCM communication shouldn't really require a Chrysler 16 connector ,just the other systems of vehicle like  ABS that use the CCD architecture. (Some early OBD2 cars might still use the underhood OBD1 style connector under hood for ABS, and you'll be SOL or need to use a older Snap On scanner. Make sure the 16 pin connector has ground and B+, and the service engine soon lamp lights works on dash  when you turn key on engine off,and the antitheft system is recognizing the ignition key.Check the ECM connector has all it's power supplies and grounds getting to it before replacing ECM unnecessarily