You'll need to actually make sure the injectors or coils are not firing, don't trust the ECU to give you that information
If you are cranking and see an RPM signal in the ECU software then the CAS should be fine. If you don't see RPM, then you need to check for 12V at the CAS, if it has 12V there, then check the signal wires for continuity and also signal back to the ECU.
Use a noid light to check injector pulse and there are a number of threads on here explaining how to do spark checks but a HEI spark tester works well.
If you have a CAS signal and RPM, then you need to check power to injectors and coils.
Start with all that