2004 GMC ENVOY XL heater

What to Use
Use a mixture of one-halfclean, drinkable waterand
one-half DEX-COOL®coolant. If you use this coolant
mixture, you don’t need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:If you use an improper coolant mixture,
your engine could overheat and be badly damaged.
The repair cost would not be covered by your
warranty. Too much water in the mixture can freeze
and crack the engine, radiator, heater core and
other parts.
If you have to add coolant more than four times a year,
have your dealer check your cooling system.
Notice:If you use the proper coolant, you do not
have to add extra inhibitors or additives which claim
to improve the system. These can be harmful.
5-25

If No Steam Is Coming From Your
Engine
If you get an engine overheat warning but see or
hear no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot
when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road, shift to
PARK (P) or NEUTRAL (N) and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues and you have not stopped,
pull over, stop, and park your vehicle right away.
If there’s still no sign of steam, you can push down the
accelerator until the engine speed is about twice as
fast as normal idle speed for at least three minutes while
you’re parked. If you still have the warning,turn off
the engine and get everyone out of the vehicleuntil it
cools down.
You may decide not to lift the hood but to get service
help right away.
5-29

The coolant level should
be at least up to the
FULL COLD mark. If it
isn’t, you may have a leak
at the pressure cap or
in the radiator hoses,
heater hoses, radiator,
water pump or somewhere
else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them.
If you do, you can be burned.
Do not run the engine if there is a leak.
If you run the engine, it could lose all coolant.
That could cause an engine re, and you
could be burned. Get any leak xed before
you drive the vehicle.If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it doesn’t, your vehicle needs service. Turn off
the engine.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
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 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.
5-31

How to Add Coolant to the Coolant
Recovery Tank
If you haven’t found a problem yet, but the coolant level
isn’t at the FULL COLD mark, add a 50/50 mixture of
clean, drinkable waterand DEX-COOL
®engine coolant
at the coolant recovery tank. SeeEngine Coolant on
page 5-24for more information.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can boil
before the proper coolant mixture will. Your
vehicle’s coolant warning system is set for the
proper coolant mixture. With plain water or the
wrong mixture, your engine could get too hot
but you would not get the overheat warning.
Your engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{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.
5-32

Compass Calibration.......................................2-36
Compass Operation.........................................2-36
Compass Variance..........................................2-37
Content Theft-Deterrent....................................2-17
Control of a Vehicle.......................................... 4-6
Convenience Net............................................2-51
Coolant
Engine Temperature Gage............................3-42
Heater, Engine............................................2-23
Cooling System..............................................5-30
Cruise Control................................................3-12
Cruise Control Light........................................3-48
CURB VIEW ACTIVATED.................................3-63
Current and Past Model Order Forms................7-13
Customer Assistance Information
Courtesy Transportation.................................. 7-8
Customer Assistance for Text
Telephone (TTY) Users............................... 7-4
Customer Assistance Offices........................... 7-4
Customer Satisfaction Procedure..................... 7-2
GM Mobility Program for Persons with
Disabilities................................................ 7-6
Reporting Safety Defects to General Motors.......7-12
Reporting Safety Defects to the Canadian
Government............................................7-12
Reporting Safety Defects to the United States
Government............................................7-11
Roadside Assistance Program......................... 7-7
Service Publications Ordering Information........7-12D
Daytime Running Lamps (DRL).........................3-17
Defensive Driving............................................. 4-2
Defogging and Defrosting.........................3-23, 3-29
Delayed Locking.............................................2-10
Dinghy Towing................................................4-46
Doing Your Own Service Work........................... 5-3
Dolly Towing..................................................4-48
Dome Lamp Override......................................3-19
Dome Lamps.................................................3-20
Door
Delayed Locking..........................................2-10
Locks.......................................................... 2-8
Power Door Locks......................................... 2-9
Programmable Automatic Door Locks.............2-10
Rear Door Security Locks.............................2-13
Driver
Position, Safety Belt.....................................1-14
DRIVER DOOR AJAR.....................................3-62
Driver Information Center (DIC).........................3-51
DIC Operation and Displays..........................3-51
DIC Warnings and Messages........................3-60
Driving
At Night.....................................................4-30
City...........................................................4-34
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Freeway.....................................................4-35
4

Driving (cont.)
Hill and Mountain Roads..............................4-38
In Rain and on Wet Roads...........................4-31
Winter........................................................4-40
Driving Across an Incline..................................4-26
Driving Downhill..............................................4-24
Driving in Mud, Sand, Snow or Ice....................4-28
Driving in Water..............................................4-28
Driving On Grades..........................................4-63
Driving on Off-Road Hills.................................4-21
Driving on Snow or Ice....................................4-41
Driving Through Deep Standing Water...............4-33
Driving Through Flowing Water.........................4-33
Driving Uphill..................................................4-22
Driving with a Trailer.......................................4-61
Dual Automatic Climate Control System.............3-25
Dual Climate Control System............................3-22
DVD
Rear Seat Entertainment System..................3-106
DVD Distortion..............................................3-117
DVD Messages.............................................3-117
DVD Player..................................................3-110
E
Electrical System
Add-On Equipment......................................5-96
Fuses and Circuit Breakers...........................5-97
Headlamps.................................................5-96Electrical System (cont.)
Power Windows and Other Power Options......5-96
Windshield Wiper Fuses...............................5-96
Electronically Controlled Air Suspension
System......................................................4-54
Emergency Release for Opening Liftgate............2-14
Emissions Inspection and Maintenance
Programs...................................................3-45
Engine
Air Cleaner/Filter.........................................5-21
Battery.......................................................5-42
Change Engine Oil Light...............................3-47
Check and Service Engine Soon Light............3-43
Coolant......................................................5-24
Coolant Heater............................................2-23
Coolant Temperature Gage...........................3-42
Drive Belt Routing.......................................6-16
Engine Compartment Overview......................5-12
Exhaust.....................................................2-34
Fan Noise..................................................5-36
Oil .............................................................5-16
Overheating................................................5-28
Reduced Power Light...................................3-48
Starting......................................................2-21
Engine Compartment Fuse Block......................5-97
ENGINE COOLANT HOT/ENGINE
OVERHEATED............................................3-61
Engine Oil Additives........................................5-19
Entry Lighting.................................................3-19
Environmental Concerns..................................4-18
5

T
Tachometer....................................................3-37
Taillamps
Turn Signal Lamps......................................5-52
Testing the Alarm............................................2-18
Theft-Deterrent, Radio....................................3-119
Theft-Deterrent Systems...................................2-17
Content Theft-Deterrent................................2-17
Passlock
®...................................................2-19
Throttle, Adjustable..........................................2-22
TIGHTEN FUEL CAP......................................3-63
Tilt Wheel........................................................ 3-7
Tire Sidewall Labeling......................................5-56
Tire Size.......................................................5-59
Tire Terminology and Denitions........................5-61
Tires.............................................................5-55
Buying New Tires........................................5-67
Chains.......................................................5-71
Changing a Flat Tire....................................5-74
If a Tire Goes Flat.......................................5-73
Ination - Tire Pressure................................5-64
Inspection and Rotation................................5-65
Spare Tire..................................................5-87
Uniform Tire Quality Grading.........................5-68
Wheel Alignment and Tire Balance.................5-69
Wheel Replacement.....................................5-69
When It Is Time for New Tires......................5-66
To Use the Engine Coolant Heater....................2-23Top Strap......................................................1-37
Top Strap Anchor Location...............................1-39
Torque Lock...................................................2-32
Total Weight on Your Vehicle’s Tires..................4-59
Towing
Recreational Vehicle.....................................4-45
Towing a Trailer..........................................4-55
Your Vehicle...............................................4-45
Traction
Assist System (TAS)...................................... 4-9
Trailer Brakes.................................................4-60
Trailer Wiring Harness.....................................4-66
Transfer Case................................................5-49
Transmission
Fluid, Automatic...........................................5-22
Transmission Operation, Automatic....................2-24
Transmission, Transaxle, Transfer Case
Unit Repair Manual......................................7-12
Transportation Options...................................... 7-9
Travel Note Recorder......................................2-47
Traveling to Remote Areas...............................4-18
Trip Information..............................................3-51
Trip Odometer................................................3-37
Turn and Lane Change Signals.......................... 3-8
TURN SIGNAL ON.........................................3-61
Turn Signal/Multifunction Lever........................... 3-7
Turn Signals When Towing a Trailer..................4-63
Two-Wheel-Drive Vehicles................................4-46
14