Coolant Surge Tank Pressure Cap; Engine Overheating - GMC 2003 Yukon Owner's Manual

Coolant Surge Tank Pressure Cap

The coolant surge tank pressure cap must be fully
installed on the coolant surge tank.
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
more information on
location.

Engine Overheating

You will find a coolant temperature gage on your
vehicle's instrument panel. See Engine Coolant
Temperature Gage on page 3-46 . In addition, you will
find an ENGINE OVERHEATED, and a REDUCED
ENGINE POWER message in the DIC on the instrument
panel. See Driver Information Center (DIC) on
page 3-53 .
Overheated Engine Protection
Operating Mode (V8 Engines Only)
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, 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. 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, change the oil and reset the oil
life system. See "Engine Oil" in the Index.
5-29