2008 CHEVROLET TAHOE check engine light

Gasoline Octane
If your vehicle has the 6.2L V8 engine (VIN Code 8),
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.
For all engines except the 6.2L V8 engine (VIN Code 8),
use regular unleaded gasoline with a posted octane
rating of 87 or higher. If the octane rating is less than 87,
you might notice an audible knocking noise when you
drive, commonly referred to as spark knock. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. 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 5-6
for 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 3-44. 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 the vehicle warranty.
5-6

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 5-34.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
®can
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 the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant
in the vehicle.
5-31

Brakes
Brake Fluid
The brake master cylinder
reservoir is lled with
DOT-3 brake uid. See
Engine Compartment
Overview on page 5-16for
the location of the reservoir.
There are only two reasons why the brake uid level in
the reservoir might go down. The rst is that the brake
uid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, the uid
level goes back up. The other reason is that uid is
leaking out of the brake hydraulic system. If it is, have
the brake hydraulic system xed, since a leak means
that sooner or later the brakes will not work well.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 3-41.
Refer to the Maintenance Schedule to determine when
to check the brake uid. SeeScheduled Maintenance
on page 6-4.
5-44

{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.
5-51

Audio System(s).............................................3-78
Rear Side Window Antenna.........................3-118
Automatic Headlamp System............................3-16
Automatic Transmission
Fluid..................................................5-24, 5-27
Operation...................................................2-30
Autoride
®.......................................................4-49
Auxiliary Roof Mounted Lamp Switch.................3-18
B
Battery..........................................................5-47
Electric Power Management..........................3-19
Run-Down Protection...................................3-20
Bench Seat, Split (60/40).................................1-12
Brake
Emergencies................................................ 4-6
Brakes..........................................................5-44
System Warning Light..................................3-41
Braking........................................................... 4-4
Braking in Emergencies..................................... 4-6
Break-In, New Vehicle.....................................2-24
Bucket Seats, Rear.........................................1-18
Bulb Replacement...........................................5-61
Halogen Bulbs............................................5-61
Headlamp Aiming........................................5-58
License Plate Lamps....................................5-63
Replacement Bulbs......................................5-63
Taillamps, Turn Signal, Stoplamps
and Back-up Lamps.................................5-61
Buying New Tires...........................................5-82
C
Calibration.............................................2-47, 2-49
California Fuel.................................................. 5-6
California Perchlorate Materials Requirements....... 5-4
California Proposition 65 Warning....................... 5-4
Canadian Owners............................................... iii
Capacities and Specications..........................5-126
Carbon Monoxide...................2-12, 2-14, 2-46, 4-30
Care of
Safety Belts..............................................5-112
Cargo Cover..................................................2-72
CD, MP3 ...............................................3-95, 3-99
Center Console Storage Area...........................2-70
Center Seat...................................................1-11
Chains, Tire...................................................5-88
Charging System Light....................................3-40
Check
Engine Light...............................................3-44
Checking Things Under the Hood......................5-14
Chemical Paint Spotting.................................5-116
Child Restraints
Child Restraint Systems...............................1-57
Infants and Young Children...........................1-54
Lower Anchors and Tethers for Children..........1-61
Older Children.............................................1-50
Securing a Child Restraint in a
Rear Seat Position...................................1-69
Securing a Child Restraint in the
Center Front Seat Position........................1-72
2

Disc, MP3.............................................3-95, 3-99
Doing Your Own Service Work........................... 5-4
Dome Lamp Override......................................3-19
Dome Lamps .................................................3-18
Door
Delayed Locking..........................................2-11
Locks........................................................2-10
Power Door Locks.......................................2-10
Programmable Automatic Door Locks.............2-11
Rear Door Security Locks.............................2-11
Driver Information Center (DIC).........................3-51
DIC Operation and Displays..................3-51, 3-56
DIC Vehicle Customization............................3-67
DIC Warnings and Messages........................3-59
Driving
At Night.....................................................4-26
Before a Long Trip......................................4-28
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Highway Hypnosis.......................................4-28
Hill and Mountain Roads..............................4-29
In Rain and on Wet Roads...........................4-26
Off-Road ....................................................4-13
Recovery Hooks..........................................4-34
Rocking Your Vehicle to Get it Out.................4-34
Winter........................................................4-30
Dual Automatic Climate Control System.............3-24
DVD
Rear Seat Entertainment System..................3-105E
EDR .............................................................7-17
Electrical System
Add-On Equipment.....................................5-119
Center Instrument Panel Fuse Block.............5-121
Fuses and Circuit Breakers.........................5-119
Instrument Panel Fuse Block.......................5-120
Power Windows and Other Power Options....5-119
Underhood Fuse Block...............................5-122
Windshield Wiper Fuses.............................5-119
Electronic Immobilizer
PASS-Key
®III+...........................................2-22
Electronic Immobilizer Operation
PASS-Key
®III+...........................................2-23
Engine
Air Cleaner/Filter.........................................5-22
Check and Service Engine Soon Light............3-44
Coolant......................................................5-31
Coolant Heater............................................2-28
Coolant Temperature Gage...........................3-43
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-16
Exhaust.....................................................2-46
Fan Noise..................................................5-41
Oil .............................................................5-17
Oil Life System...........................................5-20
Overheated Protection Operating Mode...........5-36
Overheating................................................5-34
Starting......................................................2-26
4

H
Hazard Warning Flashers................................... 3-6
Head Restraints..............................................1-10
Headlamp
Aiming .......................................................5-58
Headlamps
Bulb Replacement.......................................5-61
Daytime Running Lamps...............................3-16
Exterior Lamps............................................3-14
Flash-to-Pass............................................... 3-8
Halogen Bulbs............................................5-61
High/Low Beam Changer................................ 3-8
On Reminder..............................................3-15
Heated Seats................................................... 1-5
Heater...........................................................3-22
Engine Coolant...........................................2-28
Heater...........................................................3-24
Highbeam On Light.........................................3-49
Highway Hypnosis...........................................4-28
Hill and Mountain Roads..................................4-29
Hood
Checking Things Under................................5-14
Release.....................................................5-14
Horn ............................................................... 3-6
How to Wear Safety Belts Properly...................1-34
I
Ignition Positions.............................................2-25
Infants and Young Children, Restraints...............1-54
Ination - Tire Pressure...................................5-74
Instrument Panel
Brightness..................................................3-18
Cluster.......................................................3-35
Overview..................................................... 3-4
J
Jump Starting.................................................5-48
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
6

M
Maintenance Schedule
Additional Required Services........................... 6-6
At Each Fuel Fill.........................................6-10
At Least Once a Month................................6-10
At Least Once a Year..................................6-11
Introduction.................................................. 6-2
Maintenance Footnotes.................................. 6-8
Maintenance Record....................................6-17
Maintenance Replacement Parts....................6-15
Maintenance Requirements............................. 6-2
Owner Checks and Services.........................6-10
Recommended Fluids and Lubricants.............6-13
Scheduled Maintenance................................. 6-4
Using.......................................................... 6-3
Your Vehicle and the Environment................... 6-2
Malfunction Indicator Light................................3-44
Manual Lumbar Controls.................................... 1-4
Manual Seats................................................... 1-2
Manual, Using.................................................... iv
Memory Seat, Mirrors, and Pedals...................... 1-6
Message
DIC Warnings and Messages........................3-59
Mirrors
Automatic Dimming Rearview with Compass
and Temperature Display...........................2-49
Automatic Dimming Rearview with OnStar
®,
Compass and Temperature Display.............2-47
Outside Automatic Dimming Mirror.................2-55Mirrors (cont.)
Outside Convex Mirror.................................2-55
Outside Heated Mirrors................................2-56
Outside Manual Mirrors................................2-52
Outside Power Foldaway Mirrors....................2-54
Outside Power Mirrors..................................2-53
Outside Towing Mirrors.................................2-52
Park Tilt.....................................................2-55
MP3 .....................................................3-95, 3-99
MyGMLink.com................................................ 7-5
N
Navigation System, Privacy..............................7-18
Navigation/Radio System, see
Navigation Manual.....................................3-105
New Vehicle Break-In......................................2-24
O
Odometer......................................................3-36
Odometer, Trip...............................................3-36
Off-Road Driving.............................................4-13
Off-Road Recovery..........................................4-11
Oil
Engine.......................................................5-17
Pressure Gage............................................3-47
Pressure Light.............................................3-48
Oil, Engine Oil Life System..............................5-20
8