2010 Cadillac DTS Owner's Manual - Page 212

Warning Lights, Gages, and Indicators Warning lights and gages can signal that something is wrong before it becomes serious enough to cause an expensive repair or replacement. Paying attention to the warning lights and gages could prevent injury. Warning lights come on when there might be or there is a problem with one of the vehicle's functions. Some warning lights come on briefly when the engine is started to indicate they are working. Gages can indicate when there might be or there is a problem with one of the vehicle's functions. Often gages and warning lights work together to indicate a problem with the vehicle. When one of the warning lights comes on and stays on while driving, or when one of the gages shows there could be a problem, check the section that explains what to do. Follow this manual's advice. Waiting to do repairs can be costly and even dangerous. 4-46