Some GM cars have a "camel mode" that lets them operate without any coolant for a few miles but I've never heard of it on a diesel. I think the GM system shuts down the fuel injectors on half the cylinders and the air pumping through them pulls some of the heat out. This is from the 2005 Corvette owner's manual...
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, you will notice a loss
in power and engine performance. This operating mode
allows your vehicle to be driven to a safe place in an
emergency; you may drive up to 50 miles (80 km).
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 on
page 5-14.
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, you will notice a loss
in power and engine performance. This operating mode
allows your vehicle to be driven to a safe place in an
emergency; you may drive up to 50 miles (80 km).
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 on
page 5-14.