Computerized engine diagnostics means just that, we use a computer to help diagnose the problem with the check engine or service engine soon light. Unfortunately, computers do not simply get plugged in and they tell us what is wrong, contrary to popular belief. The computers will provide the trouble code and data for sensors and some testing tools. The ASE Certified technician will also use repair information and vehicle service information to help diagnose the problem. Once the problem is found the technician will then inform the service advisor of his diagnosis. Here is some more information on check engine lights from lifehacker.