Security light flashing on 2004 Chevrolet S10

I replace the engine, and tried to crank it, the security light continue to flash. I scan it and got a U1096 & U1016 trouble code. U1016: no communication with the PCU "powertrain control module". U1096: No communication with the IPC "instrument panel cluster"

Asked by for the 2004 Chevrolet S10