2011 Cadillac DTS Owner's Manual - Page 209

Engine Coolant Temperature Warning Light The engine coolant temperature warning light comes on when the engine is very hot. Engine Coolant Temperature Gauge This gauge shows the engine coolant temperature. This light also comes on briefly when the vehicle is started. 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 the vehicle to overheat, see Overheated Engine Protection Operating Mode on page 6 ‑ 31 . See Engine Overheating on page 6 ‑ 29 and DIC Warnings and Messages on page 4 ‑ 62 for more information. It indicates when the engine has warmed up and if the cooling system is operating properly. If the gauge pointer moves into the shaded area, the engine coolant is too hot and the engine coolant temperature warning light comes on. See Engine Overheating on page 6 ‑ 29 for more information. 4-51