2008 GMC YUKON XL heating

Consistency of Readings
Always check the uid level at least twice using the
procedure described previously. Consistency (repeatable
readings) is important to maintaining proper uid
level. If readings are still inconsistent, contact your
dealer/retailer.
How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-13.
Using a funnel, add uid down the transmission dipstick
tube only after checking the transmission uid while it
is hot. A cold check is used only as a reference. If
the uid level is low, add only enough of the proper uid
to bring the level up to the HOT area for a hot check.
It does not take much uid, generally less than one pint
(0.5 L). Do not overll.Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-13.
After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
Automatic Transmission Fluid
(6-Speed Transmission)
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the transmission
uid level. The only reason for uid loss is a
transmission leak or overheating the transmission. If you
suspect a small leak, then use the following checking
procedures to check the uid level. However, if there is a
large leak, then it may be necessary to have the
vehicle towed to a dealer/retailer service department
and have it repaired before driving the vehicle further.
5-24

Consistency of Readings
Always check the uid level at least twice using the
procedures described. Consistency (repeatable
readings) is important to maintaining proper uid level. If
uid is added, it may take 15 minutes or longer to
obtain an accurate reading because of residual uid
draining down the dipstick tube. If inconsistent readings
persist, check the transmission breather to be sure it
is clean and not clogged. If readings are still
inconsistent, contact your dealer/retailer.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-31.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as they
should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at the rst maintenance
service after each 30,000 miles (50 000 km) or
24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-28

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
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
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 5-14for more
information on location.
Engine Overheating
There is a coolant temperature gage on your vehicle’s
instrument panel. SeeEngine Coolant Temperature
Gage on page 3-47.
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 3-64.
5-31

Cooling System
If your vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s){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.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. If possible,
the vehicle should be parked on a level surface. Check
the coolant level after the system cools down. Some
amount of coolant may be lost due to overheating.
5.3L Engine (4.8L and 6.0L Similar)
5-34

Tires
Your new vehicle comes with high-quality tires
made by a leading tire manufacturer. If you ever
have questions about your tire warranty and where
to obtain service, see your vehicle Warranty
booklet for details.
{CAUTION:
Poorly maintained and improperly used
tires are dangerous.
Overloading your vehicle’s tires can
cause overheating as a result of too
much exing. You could have an
air-out and a serious accident. See
Loading Your Vehicle on page 4-35.
Underinated tires pose the same
danger as overloaded tires. The
resulting accident could cause serious
injury. Check all tires frequently to
maintain the recommended pressure.
Tire pressure should be checked when
your vehicle’s tires are cold. See
Inflation - Tire Pressure on page 5-72.
CAUTION: (Continued)
CAUTION: (Continued)

Overinated tires are more likely to be
cut, punctured, or broken by a sudden
impact — such as when you hit a
pothole. Keep tires at the
recommended pressure.
Worn, old tires can cause accidents. If
the tire’s tread is badly worn, or if
your vehicle’s tires have been
damaged, replace them.
20-Inch Tires
If your vehicle has the optional 20-inch
P275/55R20 size tires, they are classied as
touring tires and are designed for on road use. The
low-prole, wide tread design is not recommended
for off-road driving. SeeOff-Road Driving on
page 4-13, for additional information.
5-64

Chemical Paint Spotting.................................5-114
Child Restraints
Child Restraint Systems...............................1-57
Infants and Young Children...........................1-54
Lower Anchors and Tethers for Children..........1-61
Older Children.............................................1-51
Securing a Child Restraint in a Rear Seat
Position..................................................1-69
Securing a Child Restraint in the Center
Front Seat Position...................................1-71
Securing a Child Restraint in the Right
Front Seat Position...................................1-72
Where to Put the Restraint...........................1-60
Cigarette Lighter.............................................3-23
Cleaning
Aluminum or Chrome-Plated Wheels.............5-113
Exterior Lamps/Lenses................................5-112
Fabric/Carpet............................................5-109
Finish Care...............................................5-112
Instrument Panel, Vinyl, and Other Plastic
Surfaces...............................................5-110
Interior.....................................................5-108
Leather....................................................5-110
Tires........................................................5-114
Underbody Maintenance.............................5-114
Washing Your Vehicle.................................5-111
Weatherstrips............................................5-111
Windshield, Backglass, and Wiper Blades......5-113Climate Control System...................................3-23
Dual Automatic............................................3-26
Outlet Adjustment........................................3-33
Rear Air Conditioning and Heating System......3-33
Rear Air Conditioning and Heating System,
Electronic................................................3-35
Clock, Setting.................................................3-82
Collision Damage Repair..................................7-11
Compass...............................................2-49, 2-52
Content Theft-Deterrent....................................2-22
Control of a Vehicle
.......................................... 4-3
Coolant
Engine Temperature Gage............................3-47
Heater, Engine............................................2-30
Surge Tank Pressure Cap.............................5-31
Cooling System..............................................5-34
Cruise Control................................................3-13
Cruise Control Light........................................3-53
Cupholder(s)..................................................2-71
Customer Assistance Information
Courtesy Transportation.................................. 7-9
Customer Assistance for Text
Telephone (TTY) Users............................... 7-5
Customer Assistance Offices........................... 7-5
Customer Satisfaction Procedure..................... 7-2
GM Mobility Reimbursement Program............... 7-6
Reporting Safety Defects to General Motors....7-14
3

Engine
Air Cleaner/Filter.........................................5-19
Check and Service Engine Soon Light............3-48
Coolant......................................................5-28
Coolant Heater............................................2-30
Coolant Temperature Gage...........................3-47
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-14
Exhaust.....................................................2-47
Fan Noise..................................................5-39
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheated Protection Operating Mode...........5-33
Overheating................................................5-31
Running While Parked..................................2-48
Starting......................................................2-28
Entry Lighting.................................................3-20
Event Data Recorders.....................................7-16
Exit Lighting...................................................3-20
Extender, Safety Belt.......................................1-50
Exterior Lamps...............................................3-16
F
Filter
Engine Air Cleaner......................................5-19
Finish Damage.............................................5-114
Flashers, Hazard Warning.................................. 3-6
Flash-to-Pass................................................... 3-9Flat Tire........................................................5-87
Flat Tire, Changing.........................................5-88
Flat Tire, Storing...........................................5-103
Fluid.....................................................5-22, 5-24
Power Steering...........................................5-39
Windshield Washer......................................5-40
Fog Lamp
Fog ...........................................................3-19
Fog Lamp Light..............................................3-53
Four-Wheel Drive....................................2-38, 5-54
Front Axle......................................................5-55
Fuel............................................................... 5-5
Additives...................................................... 5-6
California Fuel.............................................. 5-6
E85 (85% Ethanol)........................................ 5-7
Filling a Portable Fuel Container....................5-11
Filling the Tank............................................. 5-9
Fuels in Foreign Countries.............................. 5-8
Gage.........................................................3-54
Gasoline Octane........................................... 5-5
Gasoline Specications.................................. 5-6
Low Warning Light.......................................3-55
Fuses
Center Instrument Panel Fuse Block.............5-119
Fuses and Circuit Breakers.........................5-117
Instrument Panel Fuse Block.......................5-118
Underhood Fuse Block...............................5-120
Windshield Wiper.......................................5-117
5

Power (cont.)
Running Boards..........................................2-18
Seat............................................................ 1-3
Steering Fluid.............................................5-39
Windows....................................................2-20
Privacy..........................................................7-16
Event Data Recorders..................................7-16
Navigation System.......................................7-17
OnStar.......................................................7-17
Radio Frequency Identication.......................7-17
Programmable Automatic Door Locks.................2-11
R
Radio Frequency Identication (RFID), Privacy....7-17
Radios..........................................................3-81
Radio(s)........................................................3-84
Radios
Navigation/Radio System, see Navigation
Manual.................................................3-114
Rear Seat Audio........................................3-125
Reception.................................................3-129
Setting the Clock.........................................3-82
Theft-Deterrent..........................................3-127
Rainsense™ II Wipers.....................................3-10
Reading Lamps..............................................3-21
Rear Air Conditioning and Heating System.........3-33
Rear Air Conditioning and Heating System and
Electronic Climate Controls...........................3-35Rear Axle......................................................5-52
Locking........................................................ 4-6
Rear Door Security Locks................................2-12
Rear Heated Seats.........................................1-11
Rear Seat Armrest..........................................2-73
Rear Seat Audio (RSA)..................................3-125
Rear Seat Entertainment System.....................3-115
Rear Side Window Antenna............................3-130
Rear Storage Area..........................................2-73
Rear Windshield Washer/Wiper.........................3-12
Rearview Mirror, Automatic Dimming with
Compass and Temperature Display................2-52
Rearview Mirror, Automatic Dimming with OnStar
®,
Compass and Temperature Display..................2-49
Reclining Seatbacks.......................................... 1-8
Recommended Fluids and Lubricants.................6-13
Recovery Hooks.............................................4-34
Recreational Vehicle Towing.............................4-45
Remote Keyless Entry (RKE) System.................. 2-4
Remote Keyless Entry (RKE) System, Operation..... 2-5
Remote Vehicle Start........................................ 2-8
Removing the Flat Tire and Installing the
Spare Tire..................................................5-94
Removing the Spare Tire and Tools...................5-90
Replacement Bulbs.........................................5-61
Replacement Parts, Maintenance......................6-15
Reporting Safety Defects
Canadian Government..................................7-14
General Motors...........................................7-14
United States Government............................7-14
10