1)  Why is it important to get a yearly check-up? 

By giving your vehicle a yearly transmission service, tune-up and inspection, and changing the fluid and filter, you could avoid spending thousands of dollars in the future on transmission failure. If your transmission begins to slip, have it checked immediately by an automotive professional.

2)  If a check engine light comes on, what do I do? 

Take your vehicle to an auto repair shop for a free diagnostic check. Most repair facilities will do this for free. The problem could be minor but it also could be major; early detection could save you thousands of dollars.