Page 139 of 684

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. Your vehicle
may also have an internal thermostat in the
plug end of the cord. This will prevent operation of
the engine coolant heater when the temperature
is at or above 0°F (−18°C) as noted on the cord.
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical
cord. The cord is located on the driver’s
side of the engine compartment, near
the power steering uid reservoir.
3. Plug the cord 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 285 of 684

FUEL LEVEL LOW
This message displays and a chime sounds if the
fuel level is low. Refuel as soon as possible.
SeeFuel Gage on page 268andFuel on page 490
for more information.
HOOD OPEN
This message displays and a chime sounds if the
hood is not fully closed. Stop and turn off the
vehicle, check the hood for obstructions, and close
the hood again. Check to see if the message
still appears on the DIC.
LEFT REAR DOOR OPEN (Crew Cab)
This message displays and a chime sounds if the
driver’s side rear door is not fully closed and
the vehicle is in a drive gear. Stop and turn off the
vehicle, check the door for obstructions, and
close the door again. Check to see if the message
still appears on the DIC.
OIL PRESSURE LOW STOP ENGINE
Notice:If you drive your vehicle while
the engine oil pressure is low, severe engine
damage may occur. If a low oil pressure
warning appears on the Driver Information
Center (DIC), stop the vehicle as soon as
possible. Do not drive the vehicle until the
cause of the low oil pressure is corrected. See
Engine Oil (Gasoline Engine) on page 502
for more information.
This message displays if low oil pressure levels
occur. Stop the vehicle as soon as safely possible
and do not operate it until the cause of the low
oil pressure has been corrected. Check the oil as
soon as possible and have your vehicle serviced
by your dealer. SeeEngine Oil (Gasoline Engine)
on page 502.
285
Page 491 of 684

Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you might notice an audible
knocking noise when you drive, commonly referred
to as spark knock. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible. If
you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, the 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 492for 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 262. 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.
491
Page 498 of 684
Checking Things Under
the Hood
{CAUTION:
An electric engine cooling fan can start
even when the engine is not running.
To avoid injury, always keep hands,
clothing, and tools away from any engine
cooling fan.
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
Hood Release
To open the hood do the following:
1. Pull the handle with
this symbol on it. It
is located inside
the vehicle to the left
of the brake
pedal.
498
Page 499 of 684
2. Then go to the front of the vehicle and locate
the secondary hood release. This is located
under the hood, near the center of the grille.
3. Push the secondary hood release to the right.
4. Lift the hood.
Before closing the hood, be sure all the ller
caps are on properly. Then bring the hood from
full open to within 6 inches (152 mm) from the
closed position, pause, then push the front
center of the hood with a swift, rm motion to
fully close the hood.
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Page 500 of 684
Engine Compartment Overview
If your vehicle has the DURAMAX®Diesel engine, see the DURAMAX®Diesel manual for more
information.
When you open the hood on the 5.3L engine (4.3L, 4.8L and 6.0L similar), this is what you will see:
500
Page 518 of 684

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.
CAUTION: (Continued)
CAUTION: (Continued)
SeeOverheated Engine Protection
Operating Mode (V8 Engines Only) on
page 520for 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
(V8 Engines Only) on page 520for information
on driving to a safe place in an emergency.
518
Page 535 of 684

3. Get the vehicles close enough so the jumper
cables can reach, but be sure the vehicles are
not touching each other. If they are, it could
cause an unwanted ground connection.
You would not be able to start your vehicle,
and the bad grounding could damage the
electrical systems.
To avoid the possibility of the vehicles rolling,
set the parking brake rmly on both vehicles
involved in the jump start procedure. Put
the automatic transmission in PARK (P) or a
manual transmission in NEUTRAL before
setting the parking brake. If you have a
four-wheel-drive vehicle, be sure the transfer
case is in a drive gear, not in NEUTRAL.
Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty.
Always turn off your radio and other
accessories when jump starting your vehicle.4. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the
cigarette lighter or the accessory power
outlets. Turn off the radio and all the lamps
that are not needed. This will avoid sparks and
help save both batteries. And it could save
the radio!
5. Open the hood on the other vehicle and
locate the positive (+) and negative (−)
terminal locations on that vehicle.
The positive (+) terminal, is located under a
red plastic cover at the positive battery
post. To uncover the positive (+) terminal,
open the red plastic cover.
535