How to diagnose an engine light on an Audi A4?

My engine light just turned on in my Audi A4 and I'm not sure what caused it. Can anyone provide some guidance on how to diagnose the issue?

First, try using an OBD-II scanner to read the error code. If the code is related to the emissions system, it could be a simple fix like a loose gas cap. If the code is related to the engine, it's best to take it to a certified mechanic for further diagnosis.

Before heading to a mechanic, try checking your car's manual for troubleshooting tips. It could save you time and money if it's a simple fix you can do yourself.

If you don't have access to an OBD-II scanner, some auto parts stores offer free code readings. Just be aware that the employees may not be certified mechanics and their recommendations should be taken with a grain of salt.