2008 GMC YUKON check engine light

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

It is not a good idea to top off the brake uid. Adding
brake uid will not correct a leak. If uid is added when
the linings are worn, there will be too much uid
when new brake linings are installed. Add or remove
brake uid, as necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system. See “Checking Brake Fluid”
in this section.
When the brake uid falls to a low level, the brake
warning light will come on. SeeBrake System Warning
Light on page 3-44.
Refer to the Maintenance Schedule to determine when
to check the brake uid. SeeScheduled Maintenance
on page 6-4.
Checking Brake Fluid
The brake uid can be checked without taking off the
cap by looking at the brake uid reservoir.
The uid level should be
above MIN. If it is not,
have the brake hydraulic
system checked to
see if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not over
the MAX mark.
5-42

{CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing
this, and some have been blinded. Use a
ashlight if you need more light.
Be sure the battery has enough water. You do
not need to add water to the battery installed
in your new vehicle. But if a battery has ller
caps, be sure the right amount of uid is there.
If it is low, add water to take care of that rst.
If you do not, explosive gas could be present.
Battery uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ush the place
with water and get medical help immediately.
{CAUTION:
Fans or other moving engine parts can injure
you badly. Keep your hands away from moving
parts once the engine is running.
5. Check that the jumper cables do not have loose or
missing insulation. If they do, you could get a
shock. The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go to
positive (+) or to a remote positive (+) terminal if
the vehicle has one. Negative (−) will go to a heavy,
unpainted metal engine part or to a remote
negative (−) terminal if the vehicle has one.
Do not connect positive (+) to negative (−)oryou
will get a short that would damage the battery
and maybe other parts too. And do not connect the
negative (−) cable to the negative (−) terminal on
the dead battery because this can cause sparks.
5-49

(c)Visually inspect hoses and have them replaced if they
are cracked, swollen, or deteriorated. Inspect all pipes,
fittings, and clamps; replace with genuine parts as
needed. To help ensure proper operation, a pressure test
of the cooling system and pressure cap and cleaning the
outside of the radiator and air conditioning condenser is
recommended at least once a year.
(d)Inspect wiper blades for wear, cracking, or
contamination. Clean the windshield and wiper blades, if
contaminated. Replace wiper blades that are worn or
damaged. See Windshield Wiper Blade Replacement on
page 5-62andWindshield, Backglass, and Wiper
Blades on page 5-113 for more information.
(e)Make sure the safety belt reminder light and safety
belt assemblies are working properly. Look for any
other loose or damaged safety belt system parts. If you
see anything that might keep a safety belt system
from doing its job, have it repaired. Have any torn or
frayed safety belts replaced. Also see Checking
the Restraint Systems on page 1-92.
(f)Lubricate all key lock cylinders, hood latch assembly,
secondary latch, pivots, spring anchor, release pawl,
rear compartment hinges, outer liftgate handle pivot
points, rear door detent link, roller mechanism, liftgate
handle pivot points, latch bolt, fuel door hinge, cargo
door hinge, locks, and folding seat hardware. More
frequent lubrication may be required when exposed to
a corrosive environment.Applying silicone grease on weatherstrips with a clean
cloth will make them last longer, seal better, and
not stick or squeak.
(g)Check vent hose at transfer case for kinks and
proper installation.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police, or delivery
service.
(i)Drain, flush, and refill cooling system. This service
can be complex; you should have your dealer/retailer
perform this service. See Engine Coolant on page 5-28
for what to use. Inspect hoses. Clean radiator,
condenser, pressure cap, and filler neck. Pressure test
the cooling system and pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition. Check
that the purge valve works properly, if equipped.
Replace as needed.
6-8

Audio System (cont.)
Rear Seat Audio (RSA)...............................3-125
Setting the Clock.........................................3-82
Theft-Deterrent Feature...............................3-127
XM™ Satellite Radio Antenna System...........3-130
Audio System(s).............................................3-84
Rear Side Window Antenna.........................3-130
Automatic Headlamp System............................3-18
Automatic Transmission
Fluid..................................................5-22, 5-24
Operation...................................................2-31
Autoride
®.......................................................4-49
Auxiliary Roof Mounted Lamp Switch.................3-19
B
Battery..........................................................5-45
Electric Power Management..........................3-21
Run-Down Protection...................................3-22
Bench Seat, Split (60/40).................................1-12
Brake
Emergencies................................................ 4-6
Brakes..........................................................5-41
System Warning Light..................................3-44
Braking........................................................... 4-4
Braking in Emergencies..................................... 4-6
Break-In, New Vehicle.....................................2-26
Bucket Seats, Rear.........................................1-18Bulb Replacement...........................................5-59
Halogen Bulbs............................................5-59
Headlamp Aiming........................................5-56
License Plate Lamps....................................5-61
Replacement Bulbs......................................5-61
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps........................................5-60
Buying New Tires...........................................5-80
C
Calibration.............................................2-49, 2-52
California Fuel.................................................. 5-6
California Perchlorate Materials Requirements....... 5-4
California Proposition 65 Warning....................... 5-4
Canadian Owners................................................ ii
Capacities and Specications..........................5-124
Carbon Monoxide...........2-13, 2-15, 2-47, 4-30, 4-49
Care of
Safety Belts..............................................5-110
Cargo Cover..................................................2-73
CD, MP3 ............................................3-103, 3-108
Center Console Storage Area...........................2-71
Center Seat...................................................1-11
Chains, Tire...................................................5-86
Charging System Light....................................3-43
Check
Engine Light...............................................3-48
Checking Things Under the Hood......................5-12
2

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

G
Gage
Engine Coolant Temperature.........................3-47
Fuel..........................................................3-54
Oil Pressure...............................................3-51
Speedometer..............................................3-39
Tachometer.................................................3-39
Voltmeter Gage...........................................3-44
Garage Door Opener.......................................2-64
Gasoline
Octane........................................................ 5-5
Specications............................................... 5-6
Glove Box.....................................................2-71
GM Mobility Reimbursement Program.................. 7-6
H
Hazard Warning Flashers................................... 3-6
Head Restraints..............................................1-10
Headlamp
Aiming.......................................................5-56
Headlamps
Bulb Replacement.......................................5-59
Daytime Running Lamps...............................3-17
Exterior Lamps............................................3-16
Flash-to-Pass............................................... 3-9
Halogen Bulbs............................................5-59
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-17Heated Seats................................................... 1-5
Heater...........................................................3-23
Heater...........................................................3-26
Highbeam On Light.........................................3-53
Highway Hypnosis...........................................4-28
Hill and Mountain Roads..................................4-29
Hood
Checking Things Under................................5-12
Release.....................................................5-13
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-35
I
Ignition Positions.............................................2-26
Infants and Young Children, Restraints...............1-54
Ination - Tire Pressure...................................5-72
Instrument Panel
Overview..................................................... 3-4
Instrument Panel (I/P)
Brightness..................................................3-20
Cluster.......................................................3-38
J
Jump Starting.................................................5-46
6

O
Odometer......................................................3-39
Odometer, Trip...............................................3-39
Off-Road Driving.............................................4-13
Off-Road Recovery..........................................4-11
Oil
Engine.......................................................5-15
Pressure Gage............................................3-51
Pressure Light.............................................3-52
Oil, Engine Oil Life System..............................5-18
Older Children, Restraints................................1-51
Online Owner Center........................................ 7-4
OnStar, Privacy..............................................7-17
OnStar
®System, see OnStar®Manual...............2-60
Operation, Universal Home Remote System........2-64
Other Warning Devices...................................... 3-6
Outlet Adjustment............................................3-33
Outlets
Accessory Power.........................................3-22
Outside
Automatic Dimming Mirror.............................2-57
Convex Mirror.............................................2-57
Heated Mirrors............................................2-57
Manual Mirrors............................................2-54
Power Foldaway Mirrors...............................2-56
Power Mirrors.............................................2-55
Trailer-Tow Mirrors.......................................2-54Overheated Engine Protection
Operating Mode..........................................5-33
Owner Checks and Services.............................. 6-9
Owners, Canadian............................................... ii
P
Paint, Damage..............................................5-114
Park Aid........................................................2-58
Park Brake....................................................2-43
Park (P)
Shifting Into................................................2-44
Shifting Out of............................................2-46
Park Tilt Mirrors..............................................2-57
Parking
Assist........................................................2-58
Over Things That Burn.................................2-46
Passenger Airbag Status Indicator.....................3-41
Passenger Sensing System..............................1-85
Passing.........................................................4-11
PASS-Key
®III+..............................................2-24
PASS-Key®III+ Operation................................2-24
Perchlorate Materials Requirements, California...... 5-4
Power
Door Locks.................................................2-11
Electrical System.......................................5-117
Liftgate......................................................2-15
Lumbar Controls........................................... 1-4
Retained Accessory (RAP)............................2-27
9