2004 Cadillac XLR Owner's Manual - Page 247

Coolant Surge Tank Pressure Cap Notice: If the pressure cap is not tightly installed, coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured. See Engine Compartment Overview on page 5-12 for information on location. Overheated Engine Protection Operating Mode This operating mode allows your vehicle to be driven to a safe place in an emergency situation. If an overheated engine condition exists and the DIC message ENGINE HOT, STOP ENGINE is displayed, an overheat protection mode which alternates firing groups of cylinders helps prevent engine damage. In this mode, you will notice a significant loss in power and engine performance. Driving extended miles (km) in the overheat protection mode should be avoided. Engine Overheating You will find an COOLANT OVER TEMP message or an ENGINE HOT, STOP ENGINE message displayed in the Driver Information Center (DIC). You will also hear a chime. There is also an engine coolant temperature gage on the instrument panel cluster. See Engine Coolant Temperature Gage on page 3-49. Notice: After driving in the overheated engine protection operating mode, to avoid engine damage, allow the engine to cool before attempting any repair. The engine oil will be severely degraded. Repair the cause of coolant loss, change the oil and reset the oil life system. See "Engine Oil" in the Index. 5-23