What is the best way to troubleshoot engine warning lights on an Audi?

I recently purchased a used Audi and the engine warning light has come on. How can I properly diagnose and fix the issue without going to a dealership?

The first step is to check the fault codes using an OBD-II scanner. This will give you a better understanding of what is causing the warning light to come on. Make sure to do research on the specific codes to narrow down the issue.

Check the basics such as the gas cap, oil level, and coolant levels. These simple things can sometimes be the cause of the warning light. Make sure everything is properly tightened or filled.