2008 GMC YUKON DENALI open hood

The vehicle cannot be remote started if the key is in the
ignition, the hood is not closed, or if there is an
emission control system malfunction and the check
engine light comes on.
Also, the engine will turn off during a remote vehicle
start if the coolant temperature gets too high or if the oil
pressure gets low.
Vehicles that have the remote vehicle start feature are
shipped from the factory with the remote vehicle
start system enabled. The system may be enabled or
disabled through the DIC. See “REMOTE START” under
DIC Vehicle Customization (With DIC Buttons) on
page 3-64for additional information. If your vehicle does
not have DIC buttons, see your dealer/retailer to
enable or disable the remote vehicle start system.″
Remote Start Ready
If your vehicle does not have the remote vehicle start
feature, it may have the remote start ready feature. This
feature allows your dealer/retailer to add the
manufacturer’s remote vehicle start feature.
If your vehicle has the remote start ready feature, the
RKE transmitter will have an extended range that allows
locking or unlocking of the vehicle from approximately
197 feet (60 m) away.
See your dealer/retailer if you would like to add the
manufacturer’s remote vehicle start feature to your
vehicle.
Doors and Locks
Door Locks
{CAUTION:
Unlocked doors can be dangerous.
Passengers, especially children, can easily
open the doors and fall out of a moving
vehicle. When a door is locked, the handle
will not open it. You increase the chance
of being thrown out of the vehicle in a
crash if the doors are not locked. So, wear
safety belts properly and lock the doors
whenever you drive.
Young children who get into unlocked
vehicles may be unable to get out. A child
can be overcome by extreme heat and can
suffer permanent injuries or even death
from heat stroke. Always lock your vehicle
whenever you leave it.
Outsiders can easily enter through an
unlocked door when you slow down or
stop your vehicle. Locking your doors can
help prevent this from happening.
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Adjustable Throttle and Brake Pedal
On vehicles with this feature, you can change the
position of the throttle and brake pedals.
This feature is designed for shorter drivers, since the
pedals cannot move farther away from the standard
position, but can move toward the driver for better pedal
reach.
No adjustment to the pedals can be made when the
vehicle is in REVERSE (R) or while using the cruise
control.
The switch used to adjust
the pedals is located on
the instrument panel below
the climate control
system.Press the arrow at the bottom of the switch to move the
pedals closer to your body. Press the arrow at the top of
the switch to move the pedals away from your body.
Before you start driving, fully press the brake pedal to
conrm the adjustment is right for you. While driving,
make only small adjustments.
Your vehicle may have a memory function which lets
pedal settings be saved and recalled. SeeMemory Seat,
Mirrors, and Pedals on page 1-4for more information.
Engine Coolant Heater
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. 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 is located on the driver’s side of the
engine compartment, near the power steering
uid reservoir.
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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 5-26
for more information.
This message displays and a chime sounds if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it
is safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-26for further
information.
This message also 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/retailer for service
as soon as possible.
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 3-48andFuel on page 5-5for 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
This message displays and a chime sounds if the driver
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.
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Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
Gasoline Octane
Use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration could be slightly reduced,
and you might notice a slight audible knocking noise,
commonly referred to as spark knock. If the octane is less
than 87, you might 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 could
damage the engine. If you are using gasoline rated at 87
octane or higher and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
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 5-6for
additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. 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 specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-42. 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 your warranty.
5-5

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing, and tools away
from any underhood electric 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 lower left
of the steering wheel.
5-10

2. Then go to the front of the vehicle and locate
the secondary hood release, 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.
5-11

Engine Compartment Overview
When you open the hood on the 6.2L engine this is what you will see:
5-12

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 5-28for 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. SeeOverheated Engine
Protection Operating Mode on page 5-28for
information on driving to a safe place in an
emergency.
If No Steam Is Coming From Your
Engine
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message,
along with a low coolant condition, 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. SeeTowing a Trailer on page 4-42.
5-27