ECU GMC YUKON DENALI 2008 Service Manual

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

If the word ON or the on symbol is lit on the passenger
airbag status indicator, it means that the right front
passenger’s frontal airbag is enabled (may inate).
{CAUTION:
If the on indicator comes on when you have a
rear-facing child restraint installed in the right
front passenger’s seat, it means that the
passenger sensing system has not turned off
the passenger’s frontal airbag. A child in a
rear-facing child restraint can be seriously
injured or killed if the right front passenger’s
airbag inates. This is because the back of the
rear-facing child restraint would be very close
to the inating airbag. Do not use a rear-facing
child restraint in the right front passenger’s
seat if the airbag is turned on.
{CAUTION:
Even though the passenger sensing system is
designed to turn off the right front passenger’s
frontal airbag if the system detects a rear-facing
child restraint, no system is fail-safe, and no
one can guarantee that an airbag will not deploy
under some unusual circumstance, even
though it is turned off. We recommend that
rear-facing child restraints be secured in the
rear seat, even if the airbag is off.
If the word OFF or the off symbol is lit on the airbag
status indicator, it means that the passenger sensing
system has turned off the right front passenger’s frontal
airbag. SeePassenger Sensing System on page 1-85
for more on this, including important safety information.
3-36

Oil Pressure Light
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.This light will come on
briey when you start your
engine. If it does not,
have your vehicle serviced.
When the light comes on and stays on, it means that oil
is not owing through your engine properly. You
could be low on oil and you might have some other
system problem.
Security Light
For information regarding
this light and the vehicle’s
security system, see
Content Theft-Deterrent on
page 2-22.
3-46

No Artist Info:No artist information is available at this
time on this channel. The system is working properly.
No Title Info:No song title information is available
at this time on this channel. The system is working
properly.
No CAT Info:No category information is available at
this time on this channel. The system is working
properly.
No Information:No text or informational messages are
available at this time on this channel. The system is
working properly.
CAT Not Found:There are no channels available for
the selected category. The system is working properly.
XM TheftLocked:The XM receiver in the vehicle
could have previously been in another vehicle. For
security purposes, XM™ receivers cannot be swapped
between vehicles. If this message appears after
having your vehicle serviced, check with your
dealer/retailer.
XM Radio ID:If tuned to channel 0, this message
alternates with the XM Radio eight digit radio ID label.
This label is needed to activate the service.
Unknown:If this message is received when tuned to
channel 0, there could be a receiver fault. Consult
with your dealer/retailer.Check XM Receivr:If this message does not clear
within a short period of time, the receiver could have a
fault. Consult with your dealer/retailer.
XM Not Available:If this message does not clear
within a short period of time, the receiver could have a
fault. Consult with your dealer/retailer.
Navigation/Radio System
Your vehicle may have a navigation radio system.
The navigation system has built-in features intended to
minimize driver distraction. Technology alone, no
matter how advanced, can never replace your own
judgment. See the Navigation System manual for some
tips to help you reduce distractions while driving.
Rear Seat Entertainment (RSE)
System
Your vehicle may have a DVD Rear Seat Entertainment
(RSE) system. The RSE system works with the vehicle’s
audio system. The DVD player is part of the front radio.
The RSE system includes a radio with a DVD player, a
video display screen, audio/video jacks, two wireless
headphones, and a remote control. SeeRadio(s) (MP3)
on page 3-76for more information on the vehicle’s
audio/DVD system.
3-105

Loading Your Vehicle for Off-Road
Driving
{CAUTION:
Cargo on the load oor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.
Unsecured cargo on the load oor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by ying objects. Secure the cargo
properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the
roof. Keep cargo in the cargo area as far
forward and low as possible.There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the load oor and
forward of the rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain does not toss things around.
You will nd other important information in this manual.
SeeLoading Your Vehicle on page 4-34andTires
on page 5-55.
Environmental Concerns
Off-road driving can provide wholesome and satisfying
recreation. However, it also raises environmental
concerns. We recognize these concerns and urge every
off-roader to follow these basic rules for protecting
the environment:
Always use established trails, roads, and areas that
have been specially set aside for public off-road
recreational driving; obey all posted regulations.
Avoid any driving practice that could damage the
environment — shrubs, owers, trees, grasses — or
disturb wildlife. This includes wheel-spinning,
breaking down trees, or unnecessary driving through
streams or over soft ground).
4-15

Winter Driving
Here are some tips for winter driving:
Have your vehicle in good shape for winter.
You might want to put winter emergency supplies in
your vehicle.
Include an ice scraper, a small brush or broom, a
supply of windshield washer uid, a rag, some winter
outer clothing, a small shovel, a ashlight, a red
cloth, and a couple of reective warning triangles. And,
if you will be driving under severe conditions, include
a small bag of sand, a piece of old carpet, or a couple of
burlap bags to help provide traction. Be sure you
properly secure these items in your vehicle.
Also seeTires on page 5-55.
Driving on Snow or Ice
Most of the time, those places where the tires meet the
road probably have good traction.
However, if there is snow or ice between the tires and
the road, you can have a very slippery situation.
You have a lot less traction, or grip, and need to be
very careful.What is the worst time for this? Wet ice. Very cold snow
or ice can be slick and hard to drive on. But wet ice
can be even more trouble because it can offer the least
traction of all. You can get wet ice when it is about
freezing, 32°F (0°C), and freezing rain begins to fall. Try
to avoid driving on wet ice until salt and sand crews
can get there.
Whatever the condition — smooth ice, packed, blowing,
or loose snow — drive with caution.
4-29

If you put things inside your vehicle – like suitcases,
tools, packages, or anything else – they go as fast
as the vehicle goes. If you have to stop or turn
quickly, or if there is a crash, they’ll keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
CAUTION: (Continued)
CAUTION: (Continued)

Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.
There’s also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving” underOff-Road
Driving on page 4-13.
4-39

Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to pull
a trailer are all important. It can also depend on any
special equipment that you have on your vehicle,
and the amount of tongue weight the vehicle can carry.
See “Weight of the Trailer Tongue” later in this
section for more information.Maximum trailer weight is calculated assuming only the
driver is in the tow vehicle and it has all the required
trailering equipment. The weight of additional optional
equipment, passengers and cargo in the tow vehicle
must be subtracted from the maximum trailer weight.
Use the following chart to determine how much
your vehicle can weigh, based upon your vehicle model
and options.
Vehicle Axle Ratio Maximum Trailer Weight *GCWR
Yukon Denali 3.42 7,900 lbs (3 583 kg) 14,000 lbs (6 350 kg)
Yukon XL Denali 3.42 7,900 lbs (3 583 kg) 14,000 lbs (6 350 kg)
*The Gross Combination Weight Rating (GCWR) in the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be
exceeded.
You can ask your dealer for our trailering information or
advice, or you can write us at our Customer Assistance
Offices. SeeCustomer Assistance Offices on page 7-5
for more information.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important weight
to measure because it affects the total or gross weight of
your vehicle. The Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any cargo you may carry in
it, and the people who will be riding in the vehicle.
4-45

Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
4-51

Adding Coolant
If more coolant is needed, add the proper DEX-COOL®
coolant mixture at the surge tank, but only when the
engine is cool.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When replacing the pressure cap, make sure it is
hand-tight and fully seated.
Coolant Surge Tank Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may
occur. Be sure the cap is properly and tightly
secured.
The coolant surge tank pressure cap must be fully
installed on the coolant surge tank. SeeEngine
Compartment Overview on page 5-12for more
information on location.
Engine Overheating
There is a coolant temperature gage on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-41.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the Driver
Information Center (DIC) on the instrument panel.
SeeDIC Warnings and Messages on page 3-56.
5-26