GM Service Manual Online
For 1990-2009 cars only

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. A low coolant and/or 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 .