trailer GMC ENVOY 2007 Owner's Guide

6. Start the engine and let it run until you can
feel the upper radiator hose getting hot.
Watch out for the engine cooling fan.
7. By this time, the coolant level inside the
radiator ller neck may be lower. If the level is
lower, add more of the proper DEX-COOL
®
coolant mixture through the ller neck until the
level reaches the base of the ller neck.8. Then replace the pressure cap. At any time
during this procedure if coolant begins to ow
out of the ller neck, reinstall the pressure
cap. Be sure the pressure cap is hand-tight
and fully seated.
Engine Fan Noise
Your vehicle has a clutched engine cooling fan.
When the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most
everyday driving conditions the clutch is not
engaged. This improves fuel economy and reduces
fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan
speed increases when the clutch engages so
you may hear an increase in fan noise. This is
normal and should not be mistaken as the
transmission slipping or making extra shifts. It is
merely the cooling system functioning properly.
The fan will slow down when additional cooling is
not required and the clutch disengages.
You may also hear this fan noise when you start
the engine. It will go away as the fan clutch
disengages.
416

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
HeadlampFuses Usage
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up Trailer Lamps L6 Engine
494

Fuses Usage
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7 Windshield Wiper
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
15 Electric Adjustable Pedals
16Truck Body Controller,
Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle ControlFuses Usage
24Instrument Panel Cluster,
Driver Information Center
25Automatic Shift Lock Control
System
26Transmission Control Module
Canister
27 Backup
28 Powertrain Control Module 1
29 Oxygen Sensor
30 Air Conditioning
31 Truck Body Controller 1
32 Trailer
33 Anti-lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Blower
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
53 Headlamp Driver Module
54Air Injection Reactor (AIR)
Solenoid
495

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
HeadlampFuses Usage
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up Trailer Lamps V8 Engine
497

Fuses Usage
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7 Windshield Wiper
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog Lamps
12 Stoplamp
13 Cigarette Lighter
14 Ignition Coils
15Transmission Control Module
(TCM) Canister Vent
16 Truck Body Controller, Ignition 1
17 Crank
18 Airbag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle Control
24Instrument Panel Cluster,
Driver Information CenterFuses Usage
25Automatic Shift Lock Control
System
26 Engine 1
27 Backup
28 Powertrain Control Module 1
29 Powertrain Control Module
30 Air Conditioning
31 Injector Bank A
32 Trailer
33 Anti-lock Brakes (ABS)
34 Ignition A
35 Blower Motor
36 Ignition B
50 Passenger’s Side Trailer Turn
51 Driver’s Side Trailer Turn
52 Hazard Flashers
53 Transmission
54 Oxygen Sensor Bank B
55 Oxygen Sensor Bank A
56 Injector Bank B
57 Headlamp Driver Module
58 Truck Body Controller 1
59 Electric Adjustable Pedal
498

Fuses Usage
09 Rear Wiper
10 Driver Door Module
11 Amplier
12 Passenger Door Module
13 Rear Climate Controls
14 Driver Side Rear Parking Lamps
15 Blank
16Vehicle Center High-Mounted
Stoplamp (CHMSL)
17Passenger Side Rear Parking
Lamps
18 Locks
19 Liftgate Module/Driver Seat Module
20 Blank
21 Lock
23 Blank
24 Unlock
25 Blank
26 Blank
27OnStar
®Overhead Battery/OnStar®
System
28 Sunroof
29 Rainsense™ Wipers
30 Parking Lamps
Fuses Usage
31 Truck Body Controller Accessory
32 Truck Body Controller 5
33 Front Wipers
34 Vehicle Stop
35 Transmission Control Module
36 Heat Ventilation Air Conditioning B
37 Front Parking Lamps
38 Driver Side Turn Signal
39 Heat Ventilation Air Conditioning 1
40 Truck Body Controller 4
41 Radio
42 Trailer Park
43 Passenger Side Turn Signal
44 Heat Ventilation Air Conditioning
45 Rear Fog Lamps
46 Auxiliary Power 1
47 Ignition 0
48 Four-Wheel Drive
49 Blank
50 Truck Body Controller Ignition
51 Brakes
52 Truck Body Controller Run
501

(e)Make sure the safety belt reminder light and all
your belts, buckles, latch plates, retractors, and
anchorages 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
look for any opened or broken airbag coverings,
and have them repaired or replaced. The
airbag system does not need regular maintenance.
(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)Inspect hoses for cracks, chang, leaks, kinks,
and proper installation.(h)Change automatic transmission uid and lter
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, ush, and rell cooling system. This
service can be complex; you should have
your dealer perform this service. See Engine
Coolant on page 405 for what to use. Inspect
hoses. Clean radiator, condenser, pressure cap,
and ller neck. Pressure test the cooling
system and pressure cap.
(j)A uid loss in any vehicle system could indicate
a problem. Have the system inspected and
repaired and the uid level checked. Add uid if
needed.
512

Towing
Recreational Vehicle................................. 355
Towing a Trailer....................................... 362
Your Vehicle............................................. 354
Traction
StabiliTrak
®System................................. 309
Transmission
Fluid, Automatic....................................... 401
Transmission Operation, Automatic.............. 118
Trip Odometer............................................. 199
Turn and Lane-Change Signals................... 172
Turn Signal/Multifunction Lever.................... 171
U
Understanding Radio Reception................... 298
Uniform Tire Quality Grading....................... 458
Universal Home Remote System........149, 150
Operation........................................151, 156
V
Vehicle
Control..................................................... 306
Damage Warnings....................................... 5
Loading.................................................... 349
Symbols...................................................... 5
Vehicle Customization, DIC......................... 229
Vehicle Data Collection and Event Data
Recorders................................................ 538
Vehicle Identication
Number (VIN).......................................... 491
Service Parts Identication Label.............. 491
Ventilation Adjustment.................................. 194
Visors.......................................................... 109
Voltmeter Gage........................................... 205
561