2009 Cadillac STS-V Owner's Manual - Page 362

If No Steam Is Coming From The Engine Compartment An overheat warning, can indicate a serious problem. If an engine overheat warning is displayed but no steam can be seen or heard, the problem may not be too serious. Sometimes the engine can get a little too hot when the vehicle: • Climbs a long hill on a hot day. • Stops after high-speed driving. • Idles for long periods in traffic. • Tows a trailer. If the overheat warning is displayed with no sign of steam: 1. Turn the air off. 2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as necessary. 3. In heavy traffic, let the engine idle in N (Neutral) while stopped. If it is safe to do so, pull off the road, shift to P (Park) or N (Neutral) and let the engine idle. If the engine coolant temperature gage is no longer in the overheat zone or an overheat warning no longer displays, the vehicle can be driven. Continue to drive the vehicle slow for about 10 minutes. Keep a safe vehicle distance from the car in front of you. If the warning does not come back on, continue to drive normally. 5-36 If the warning continues, pull over, stop, and park the vehicle right away. If there is no sign of steam, idle the engine for three minutes while parked. If the warning is still displayed, turn off the engine until it cools down. Also, see ″Overheated Engine Protection Operating Mode″ later in this section. Overheated Engine Protection Operating Mode This operating mode allows your vehicle to be driven to a safe place in an emergency. Should an overheated engine condition exist, an overheat protection mode which alternates firing groups of cylinders helps prevent engine damage. In this mode, you will notice a loss in power and engine performance. An engine overheat warning will indicate that an overheat condition exists. Driving extended miles (km) and/or towing a trailer in the overheat protection mode should be avoided. 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 and change the oil. See Engine Oil on page 5-18.