2008 GMC YUKON DENALI engine

Tow/Haul Mode
Your vehicle has a tow/haul mode. The tow/haul mode
adjusts the transmission shift pattern to reduce shift
cycling, providing increased performance, vehicle
control, and transmission cooling when towing or hauling
heavy loads.Press the button located on the end of the shift lever to
turn the tow/haul on or off. When the tow/haul is on,
a light on the instrument panel cluster will come on.
SeeTow/Haul Mode Light on page 3-47for more
information.
Also see “Tow Haul Mode” underTowing a Trailer on
page 4-42for more information.
The tow/haul mode works with the Autoride
®feature, if
the vehicle has this, to enhance the ride when trailering or
with a loaded vehicle. SeeAutoride
®on page 4-41.
Grade Braking
Grade Braking assists when driving on a downhill grade.
It maintains the vehicle’s speed by automatically
implementing a shift schedule that uses the engine and
the transmission to slow the vehicle. This reduces
wear on the brakes system and increases control of the
vehicle. The system constantly monitors the vehicle’s
speed, acceleration, throttle position, and whether
the brake pedal is being pressed, and determines when
to keep the current vehicle speed or to slow down.
The system will then automatically command downshifts
that reduces the vehicles speed, until the brake pedal
is no longer being pressed. This indicates the desired
vehicle speed has been reached.
2-34

Shifting Into PARK (P)
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake rmly set. Your vehicle can
roll. If you have left the engine running, the
vehicle can move suddenly. You or others
could be injured. To be sure your vehicle will
not move, even when you are on fairly level
ground, use the steps that follow. If you are
pulling a trailer, seeTowing a Trailer on
page 4-42.
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into the PARK (P) position by
pulling the shift lever toward you and moving it up
as far as it will go.
3. Turn the ignition key to LOCK/OFF.
4. Remove the key and take it with you. If you can
leave your vehicle with the ignition key in your
hand, your vehicle is in PARK (P).
Leaving Your Vehicle With the Engine
Running
{CAUTION:
It can be dangerous to leave your vehicle with
the engine running. Your vehicle could move
suddenly if the shift lever is not fully in
PARK (P) with the parking brake rmly set.
And, if you leave the vehicle with the engine
running, it could overheat and even catch re.
You or others could be injured. Do not leave
your vehicle with the engine running.
If you have to leave your vehicle with the engine
running, be sure your vehicle is in PARK (P) and the
parking brake is rmly set. After the shift lever is moved
into PARK (P), hold the regular brake pedal down.
Then, see if you can move the shift lever away from
PARK (P) without rst pulling it toward you. If you can, it
means that the shift lever was not fully locked into
PARK (P).
2-36

Parking Over Things That Burn
{CAUTION:
Things that can burn could touch hot exhaust
parts under your vehicle and ignite. Do not
park over papers, leaves, dry grass, or other
things that can burn.
Engine Exhaust
{CAUTION:
Engine exhaust can kill. It contains the gas
carbon monoxide (CO), which you cannot see or
smell. It can cause unconsciousness and death.
You might have exhaust coming in if:
The exhaust system sounds strange or
different.
Your vehicle gets rusty underneath.
Your vehicle was damaged in a collision.
Your vehicle was damaged when driving
over high points on the road or over road
debris.
Repairs were not done correctly.
Your vehicle or the exhaust system has
been modied improperly.
If you ever suspect exhaust is coming into your
vehicle:
Drive it only with all the windows down to
blow out any CO; and
Have your vehicle xed immediately.
2-38

Running the Engine While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{CAUTION:
Idling the engine with the climate control
system off could allow dangerous exhaust into
your vehicle. See the earlier caution under
Engine Exhaust on page 2-38.
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the climate control fan is at the highest setting.
One place this can happen is a garage.
Exhaust — with CO — can come in easily.
NEVER park in a garage with the engine
running.
Another closed-in place can be a blizzard. See
Winter Driving on page 4-29.
{CAUTION:
It can be dangerous to get out of your vehicle
if the shift lever is not fully in PARK (P) with
the parking brake rmly set. Your vehicle can
roll. Do not leave your vehicle when the engine
is running unless you have to. If you have left
the engine running, the vehicle can move
suddenly. You or others could be injured. To
be sure your vehicle will not move, even when
you are on fairly level ground, always set the
parking brake and move the shift lever to
PARK (P).
Follow the proper steps to be sure your vehicle will not
move. SeeShifting Into PARK (P) on page 2-36.
If you are pulling a trailer, seeTowing a Trailer on
page 4-42.
2-39

Engine Coolant Temperature Gage..................3-41
Tire Pressure Light.......................................3-41
Malfunction Indicator Lamp.............................3-42
Oil Pressure Gage........................................3-45
Oil Pressure Light.........................................3-46
Security Light...............................................3-46
Fog Lamp Light............................................3-47
Cruise Control Light......................................3-47
Highbeam On Light.......................................3-47
Tow/Haul Mode Light....................................3-47
Fuel Gage...................................................3-48
Low Fuel Warning Light.................................3-48
Driver Information Center (DIC).......................3-49
DIC Operation and Displays
(Using DIC Buttons)...................................3-49
DIC Operation and Displays
(Using Trip Odometer Reset Stem)..............3-54DIC Warnings and Messages.........................3-56
DIC Vehicle Customization (With DIC Buttons). . . .3-64
Audio System(s).............................................3-73
Setting the Clock..........................................3-74
Radio(s) (MP3).............................................3-76
Using an MP3 (Radio with Six-Disc Player)......3-94
Using an MP3 (Radio with CD and DVD
Player).....................................................3-99
XM Radio Messages...................................3-104
Navigation/Radio System..............................3-105
Rear Seat Entertainment (RSE) System.........3-105
Rear Seat Audio (RSA)................................3-115
Theft-Deterrent Feature................................3-116
Audio Steering Wheel Controls......................3-117
Radio Reception.........................................3-118
Rear Side Window Antenna..........................3-119
XM™ Satellite Radio Antenna System............3-119
Section 3 Instrument Panel
3-2

The battery can be discharged at idle if the electrical
loads are very high. This is true for all vehicles. This is
because the generator (alternator) may not be
spinning fast enough at idle to produce all the power
that is needed for very high electrical loads.
A high electrical load occurs when several of the
following loads are on: headlamps, high beams, fog
lamps, rear window defogger, climate control fan at high
speed, heated seats, engine cooling fans, trailer
loads, and loads plugged into accessory power outlets.
EPM works to prevent excessive discharge of the
battery. It does this by balancing the generator’s output
and the vehicle’s electrical needs. It can increase
engine idle speed to generate more power, whenever
needed. It can temporarily reduce the power demands of
some accessories.
Normally, these actions occur in steps or levels, without
being noticeable. In rare cases at the highest levels
of corrective action, this action may be noticeable to the
driver. If so, a Driver Information Center (DIC)
message might be displayed, such as Battery Saver
Active or Service Battery Charging System. If this
message is displayed, it is recommended that the driver
reduce the electrical loads as much as possible. See
DIC Warnings and Messages on page 3-56.Battery Run-Down Protection
This feature shuts off the dome, and reading lamps
if they are left on for more than 10 minutes when
the ignition is off. This will keep the battery from
running down.
Accessory Power Outlet(s)
Accessory power outlets can be used to connect
auxiliary electrical equipment, such as a cellular
telephone or CB radio.
There are two under the climate controls, one inside the
center oor console, one on the rear of the center
oor console and one accessory power outlet in the rear
cargo area on the passenger side.
To use an accessory power outlet, remove the protective
cap. When not in use, always cover the accessory
power outlet with the protective cap.
3-21

The passenger’s temperature setting can be set to match
the driver’s temperature setting by pressing the PASS
button and turning off the PASS indicator. When the
passenger’s temperature setting is set different than the
driver’s setting, the indicator on the PASS button will
illuminate and both the driver’s side and passenger’s side
temperature displays will be shown.
Automatic Operation
AUTO (Automatic):When automatic operation is
active the system will control the inside temperature, the
air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display will change to
show the current temperature(s) and AUTO will
be lit on the display. The current delivery mode and
fan speed will also be displayed for approximately
5 seconds.
When AUTO is selected, the air conditioning
operation and air inlet will be automatically
controlled. The air conditioning compressor will run
when the outside temperature is over about
40°F (4°C). The air inlet will normally be set to
outside air.If it is hot outside, the air inlet may automatically
switch to recirculate inside air to help quickly
cool down the vehicle. The light on the button will
illuminate in recirculation.
2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes
for the system to regulate. Use the driver’s or
passenger’s temperature buttons to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C),
the system will remain at the maximum heat setting.
Choosing either maximum setting will not cause
the vehicle to heat or cool any faster.
Be careful not to cover the solar sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun load and
also turns on the headlamps. For more information on
the solar sensor, see “Sensors” later in this section.
To avoid blowing cold air in cold weather, the system will
delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pressing the fan switch will override this
delay and change the fan to a selected speed.
3-24

-(Defog):See “Defogging and Defrosting” later in
this section.
@(Recirculation):Press this button to turn the
recirculation mode on. When the button is pressed, an
indicator light comes on.
This mode keeps outside air from entering the vehicle.
It can be used to reduce outside air and prevent
odors from entering the vehicle. Recirculation may also
help cool the air inside the vehicle more quickly once
the temperature inside the vehicle is less than the
outside temperature.
The recirculation mode cannot be used with oor,
defrost, or defogging modes. If you try to select
recirculation in one of those modes, the indicator will
ash three times and turn off. The air conditioning
compressor will also come on when this mode is
activated. While in recirculation mode the windows may
fog when the weather is cold and damp. To clear the
fog, select either the defog or defrost mode and increase
the fan speed. Recirculation mode can be turned off
by pressing the button again, or turning off the engine.
Air Conditioning
#
(Air Conditioning):Press this button to turn the
air conditioning (A/C) compressor on and off. When
air conditioning is selected, an indicator light comes on
to show that the air conditioning has been activated.
Pressing this button when the outside temperature is too
cool for air conditioning will make the air conditioning
indicator ash three times and then turn off to show that
the air conditioning mode is not available. If the air
conditioning is on and the outside temperature drops
below a temperature which is too cool for air
conditioning to be effective, the air conditioning light will
turn off to show that the air conditioning mode has
been canceled.
On hot days, open the windows long enough to let hot
inside air escape. This helps to reduce the time it
takes for your vehicle to cool down. It also helps the
system to operate more efficiently.
The air conditioning system removes moisture from the
air, so a small amount of water might drip underneath
the vehicle while idling or after turning off the engine.
This is normal.
3-26