2010 Cadillac CTS Owner's Manual - Page 320

9-20 Vehicle Care If the engine is warm or hot, the coolant level should be at or above the FROID/FULL COLD line on the side of the coolant surge tank. If the engine is cold, the coolant level should be near the FROID/FULL COLD line on the side of the coolant surge tank. If it is not, there could be a leak in the cooling system. { WARNING An electric engine cooling fan under the hood can start up even when the engine is not running and can cause injury. Keep hands, clothing, and tools away from any underhood electric fan. If coolant is needed, add the proper DEX-COOL® coolant mixture at the coolant surge tank. If no coolant is visible in the surge tank, add coolant as follows: 1. Remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot. Turn the pressure cap slowly counterclockwise about one-quarter turn and then stop. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. How to Add Coolant to the Surge Tank { WARNING Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the surge tank pressure cap - even a little - they can come out at high speed. Never turn the cap when the cooling system, including the surge tank pressure cap, is hot. Wait for the cooling system and surge tank pressure cap to cool if you ever have to turn the pressure cap. { WARNING You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged.