If you see an icon of a small engine associated with the yellow signal, then it's your Check Engine light. If so, your car has detected a problem that can affect your engine's performance and operation.First check your gas cap to make sure it was securely closed and see if the engine light goes away.Otherwise, visit your local auto parts store and borrow/buy an On Board Diagnostic (OBD) scanner and plug it into the interface port under your dashboard. Then repost your question with the error code to find out if anyone has any ideas.Good luck!