Page 112 of 456

Engine Coolant Heater
Your vehicle may have this feature. In very cold
weather, 0°F (−18°C) or colder, the engine coolant
heater can help. You will get easier starting and
better fuel economy during engine warm-up.
Usually, the coolant heater should be plugged
in a minimum of four hours prior to starting your
vehicle. At temperatures above 32°F (0°C), use of
the coolant heater is not required.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical
cord. The cord is attached to the underside
of the diagonal brace, which is located above
the engine air cleaner/ lter assembly.
3. Plug it into a normal, grounded 110-volt
AC outlet.
{CAUTION:
Plugging the cord into an ungrounded
outlet could cause an electrical shock.
Also, the wrong kind of extension cord
could overheat and cause a re. You
could be seriously injured. Plug the cord
into a properly grounded three-prong
110-volt AC outlet. If the cord will not
reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug
and store the cord as it was before to keep it
away from moving engine parts. If you do
not, it could be damaged.
How long should you keep the coolant heater
plugged in? The answer depends on the outside
temperature, the kind of oil you have, and some
other things. Instead of trying to list everything here,
we ask that you contact your dealer in the area
where you will be parking your vehicle. The dealer
can give you the best advice for that particular area.
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Page 198 of 456

ENGINE OVERHEATED STOP ENGINE
Notice:If you drive your vehicle while the
engine is overheating, severe engine damage
may occur. If an overheat warning appears on
the instrument panel cluster and/or DIC, stop
the vehicle as soon as possible. SeeEngine
Overheating on page 323for more information.
This message displays along with a continuous
chime when the engine has overheated. Stop and
turn the engine off immediately to avoid severe
engine damage. SeeEngine Overheating on
page 323.
ENGINE POWER IS REDUCED
This message displays when the vehicle’s engine
power is reduced. Reduced engine power can
affect the vehicle’s ability to accelerate. If this
message is on, but there is no reduction in
performance, proceed to your destination. The
performance may be reduced the next time the
vehicle is driven. The vehicle may be driven at a
reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime
this message stays on, the vehicle should be taken
to your dealer for service as soon as possible.
ERROR
This message displays while viewing the odometer
or trip odometers if there is a problem with the
instrument panel cluster. See your dealer for
service.
FUEL LEVEL LOW
This message displays when your vehicle is low
on fuel. Re ll the fuel tank as soon as possible.
SeeFuel Gage on page 185andFilling the Tank
on page 303for more information.
HOOD OPEN
If your vehicle has the remote start feature, this
message displays when the hood is not closed
properly. When this message appears, make sure
that the hood is closed completely. SeeHood
Release on page 307.
ICE POSSIBLE DRIVE WITH CARE
This message displays when the outside air
temperature is cold enough to create icy road
conditions. Adjust your driving accordingly.
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Page 299 of 456

If your vehicle has the 5.3L V8 engine (VIN
Code C), use premium unleaded gasoline with a
posted octane rating of 91 or higher. You may
also use regular unleaded gasoline rated at
87 octane or higher, but your vehicle’s acceleration
may be slightly reduced, and you may notice a
slight audible knocking noise, commonly referred
to as spark knock. If the octane is less than
87, you may notice a heavy knocking noise when
you drive. If this occurs, use a gasoline rated
at 87 octane or higher as soon as possible.
Otherwise, you might damage your engine.
If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, your engine
needs service.
Gasoline Speci cations
At a minimum, gasoline should meet ASTM
speci cation D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 300for additional information.
California Fuel
If your vehicle is certi ed to meet California
Emissions Standards, it is designed to operate
on fuels that meet California speci cations.
See the underhood emission control label.
If this fuel is not available in states adopting
California emissions standards, your vehicle will
operate satisfactorily on fuels meeting federal
speci cations, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction Indicator
Lamp on page 181. If this occurs, return to
your authorized GM dealer for diagnosis. If it is
determined that the condition is caused by the
type of fuel used, repairs may not be covered
by your warranty.
299
Page 307 of 456
Hood Release
To open the hood, do the following:
1. Pull the interior
hood release handle
with this symbol
on it. It is located
to the left of
the parking brake
pedal.
2. Then go to the front of the vehicle and
release the secondary hood latch, located
near the center of the hood front, by pushing
the latch to the right.
3. Lift the hood.
Before closing the hood, be sure all the ller caps
are on properly. Then pull the hood down and
close it rmly.
307
Page 308 of 456
Engine Compartment Overview
When you open the hood on the 3.5L V6 engine, this is what you will see:
308
Page 310 of 456
When you open the hood on the 5.3L V8 engine, this is what you will see:
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Page 324 of 456

If Steam Is Coming From Your Engine
{CAUTION:
Steam from an overheated engine can
burn you badly, even if you just open
the hood. Stay away from the engine if
you see or hear steam coming from it.
Turn it off and get everyone away from
the vehicle until it cools down. Wait until
there is no sign of steam or coolant
before you open the hood.
If you keep driving when the vehicles
engine is overheated, the liquids in it can
catch re. You or others could be badly
burned. Stop your engine if it overheats,
and get out of the vehicle until the engine
is cool.
SeeOverheated Engine Protection
Operating Mode on page 325for
information on driving to a safe place
in an emergency.Notice:If your engine catches re because
you keep driving with no coolant, your vehicle
can be badly damaged. The costly repairs
would not be covered by your warranty. See
Overheated Engine Protection Operating Mode
on page 325for information on driving to a
safe place in an emergency.
If No Steam Is Coming From Your
Engine
An overheat warning can indicate a serious
problem.
If you get an engine overheat warning but see
or hear no steam, the problem may not be
too serious. Sometimes the engine can get a
little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
324
Page 325 of 456

If an overheat warning occurs without any sign of
steam, try this for a minute or so:
1. In heavy traffic, let the engine idle in
NEUTRAL (N) while stopped. If it is safe to
do so, pull off the road, shift to PARK (P)
or NEUTRAL (N) and let the engine idle.
2. Set the heater at the highest setting and the
fan at the highest speed and open the
windows as necessary.
If the overheat warning no longer exists, the
vehicle can be driven. Just to be safe, drive slower
for about 10 minutes. If the warning does not
come back on, the vehicle can be driven normally.
If the warning continues, and you have not
stopped, pull over, stop, and park the vehicle
right away.
If there is still no sign of steam, idle the engine
for three minutes while parked. If the warning
is still there, turn off the engine and get everyone
out of the vehicle until it cools down. Also, see
“Overheated Engine Protection Operating Mode”
later in this section.
You may decide not to lift the hood but to get
service help right away.Overheated Engine Protection
Operating Mode
This emergency operating mode allows your
vehicle to be driven to a safe place in an
emergency situation. If an overheated engine
condition exists, an overheat protection mode
which alternates ring groups of cylinders helps
prevent engine damage. In this mode, you
will notice a signi cant loss in power and engine
performance. The coolant temperature gage
will indicate 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, change the oil and reset the oil life
system. SeeEngine Oil on page 311.
325