2008 Cadillac STS Owner's Manual - Page 220

Lane Departure Warning Light Your vehicle may have the lane departure warning system. Engine Coolant Temperature Warning Light The engine coolant temperature warning light will come on when the engine is very hot. This light will also come on briefly when the vehicle is started. This light will come on green, briefly, when the vehicle is started to show that it is working. This light will also come on green if the system detects a left or right lane marking. This light will change to amber and flash and three beeps will sound if you cross a detected lane marking without using your turn signal. For more information, see the Index in the Navigation Manual. If the light does not go out or comes on and stays on while driving, there may be a problem with the cooling system. Driving with engine coolant temperature light on could cause your vehicle to overheat, see Overheated Engine Protection Operating Mode on page 5-31. See Engine Overheating on page 5-29 and DIC Warnings and Messages on page 3-80 for more information. 3-66