Installed new ecm and pcm already flashed by seller. Dash displays message "press clutch and press start button to start " car is automatic. No crank u0100
It sounds like it might have been flashed incorrectly, or there might be something in the software you can update to tell it what setup this vehicle runs. Do you have a scan tool that can access OEM level info for Dodge?
Presumably it's not happy if you just press the brake pedal and try to start instead?