
Engine Coolant Heater
If the vehicle has the DURAMAX Diesel engine, see the
DURAMAX Diesel manual for more information.
The engine coolant heater can provide easier starting
and better fuel economy during engine warm-up in cold
weather conditions at or below 0°F (−18°C). Vehicles
with an engine coolant heater should be plugged
in at least four hours before starting. An internal
thermostat in the plug-end of the cord may exist which
will prevent engine coolant heater operation at
temperatures above 0°F (−18°C).
To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord for the engine coolant heater is located
on the driver side of the engine compartment and is
attached to the hose for the power steering
reservoir.
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 fire.
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 and prevent damage.
The length of time the heater should remain plugged in
depends on several factors. Ask a dealer/retailer in
the area where you will be parking the vehicle for the
best advice on this.
2-22

If the vehicle has the 5.3L V8 engine (VIN Code 4) and
the N15 flexible fuel option, you can use either regular
unleaded gasoline or ethanol fuel containing up to 85%
ethanol (E85). SeeFuel E85 (85% Ethanol) on page 5-8.
For the 5.3L V8 engine (VIN Code 4) without the N15
option and all other gasoline engines, use only regular
unleaded gasoline.
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 specification
D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in
Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-7
for additional information.
California Fuel
If the vehicle is certified to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specifications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, the vehicle will operate
satisfactorily on fuels meeting federal specifications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and the
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-36. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by the vehicle warranty.
5-6

Filling a Portable Fuel Container
{CAUTION:
Never fill a portable fuel container while it is in
the vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
•Dispense fuel only into approved containers.
•Do not fill a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed,
or on any surface other than the ground.
•Bring the fill nozzle in contact with the inside
of the fill opening before operating the nozzle.
Contact should be maintained until the filling
is complete.
•Do not smoke while pumping fuel.
•Do not use a cellular phone while
pumping fuel.
Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine or fuel
operated heater (FOH) parts and start a fire.
These include liquids like fuel, oil, coolant, brake
fluid, windshield washer and other fluids, 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 or fuel operated heater (FOH).
5-12

Hood Release
To open the hood:
1. Pull the handle with
this symbol on it. It is
located in front of
the driver’s side door
frame near the floor.
2. Then go to the front of the vehicle and lift up
the secondary hood release, which is located
underneath the middle of the hood.3. Lift the hood, release the hood prop from its
retainer and put the hood prop into the slot in
the hood.
If your vehicle has an underhood lamp, it will
automatically come on and stay on until the hood
is closed.
Before closing the hood, be sure all of the filler caps
are on properly. Then lift the hood to relieve pressure on
the hood prop. Remove the hood prop from the slot in
the hood and return the prop to its retainer. Let the hood
down and close it firmly.
5-13

If Steam Is Coming From The Engine
Compartment
{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. Just 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 your engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop your engine if
it overheats, and get out of the vehicle until the
engine is cool.
If No Steam Is Coming From The
Engine Compartment
If an engine overheat warning is displayed but no
steam can be seen or heard, the problem may not
be too serious. Sometimes the engine can get a little
too hot when the vehicle:
•Climbs a long hill on a hot day.
•Stops after high-speed driving.
•Idles for long periods in traffic.
•Tows a trailer. See “Driving on Grades” under
Towing a Trailer on page 4-26.
If the overheat warning is displayed with no sign of
steam:
1. Turn the air off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let
the engine idle.
5-32

Notice:If you leave the radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered by
the warranty. Always turn off the radio and other
accessories when jump starting the vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlet. Turn off the
radio and all lamps that are not needed. This will
avoid sparks and help save both batteries. And it
could save the radio!
4. Open the hoods and locate the positive (+) and
negative (−) terminal locations of the other vehicle.
Your vehicle has a remote positive (+) jump
starting terminal and a remote negative (−) jump
starting terminal. You should always use these
remote terminals instead of the terminals on the
battery.The remote positive (+) terminal is located
behind a red plastic cover near the engine accessory
drive bracket on the driver’s side of the engine
compartment, below the alternator. To uncover the
remote positive (+) terminal, open the red plastic
cover.
The remote negative (−) terminal is located on the
engine drive bracket on all V8 engines and is
marked GND (Ground).
On V6 engines the remote negative (−) terminal is
located on a tab attached to the engine accessory
drive bracket and is marked GND (Ground).
5-41

Bulb Replacement
For the proper type of replacement bulbs, see
Replacement Bulbs on page 5-52.
For any bulb changing procedure not listed in this
section, contact your dealer/retailer.
Halogen Bulbs
{CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and follow
the instructions on the bulb package.
Headlamps
To remove the headlamp assembly from the vehicle and
access the bulbs:
1. Open the hood. SeeHood Release on page 5-13
for more information.
2. Remove the two bolts from the headlamp assembly.
3. Remove the two pins on the top of the headlamp
assembly. To remove the pins, turn the outer pin
clockwise and pull it straight up. To remove the
inner pin, turn it counterclockwise and pull it
straight up.
5-48