GM Service Manual Online
For 1990-2009 cars only

This emergency operating mode lets the vehicle be driven to a safe place, up to 50 miles (80 km), in an emergency situation. If an overheated engine condition exists and the messages COOLANT OVER TEMPERATURE and REDUCED ENGINE POWER are displayed, along with the check engine light, an overheat protection mode which alternates firing groups of cylinders helps prevent engine damage. In this mode, there is a significant loss in power and engine performance.

Driving extended distances 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, change the oil and reset the oil life system. See Engine Oil .