Fan GMC ENVOY 2007 Owner's Guide

H(Vent):This mode directs air to the instrument
panel outlets.
)(Bi-Level):This mode directs approximately
half of the air to the instrument panel outlets, then
directs the remaining air to the oor outlets.
A little air is directed toward the windshield and the
side window outlets. Cooler air is directed to the
upper outlets and warmer air to the oor outlets.
6(Floor):This mode directs most of the air to the
oor outlets. Some air also comes out of the
defroster and side window outlets. The recirculation
button cannot be selected in oor mode.
@(Recirculation):Press this button to turn
recirculation mode on or off. When this button is
pressed, an indicator light in the button will also
come on to let you know that it is activated.
Recirculation mode is used to recirculate the air
inside of your vehicle. Use this mode to help
prevent outside odors and/or dust from entering
your vehicle or to help cool the air inside of your
vehicle more quickly. Recirculation mode can be
used with vent and bi-level modes, but it cannot be
used with oor, defog or defrost modes. Defog and
defrost modes are described later in this section.If recirculation mode is selected with oor, defog, or
defrost modes, the indicator will ash three times
and then turn off indicating the selection is not
available.
You may also notice that the air conditioning
compressor will run while in recirculation mode.
This is normal and will help to prevent fogging.
If the weather is cold and damp, the system may
cause the windows to fog while using recirculation
mode. If the windows do start to fog, select defog or
defrost mode and increase fan speed.
Recirculation mode, if selected, will be cleared
when the engine is turned off.#A/C (Air Conditioning):Press this button to
manually turn the air conditioning system on or off.
When the system is on, the system will
automatically begin to cool and dehumidify the air
inside of your vehicle. The air conditioning
symbol will appear on the display when the air
conditioning is on and will turn off when the
air conditioning is off.
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If you turn the air conditioning off while in front
defrost or defog mode, the air conditioning symbol
will turn off, however, the A/C compressor will
remain on to help de-humidify the air inside
the vehicle. If one of the other modes is selected
the compressor will then turn the A/C off until
it is selected again or the AUTO button is pressed.
To avoid fogging the inside glass on rainy and
humid days at a temperature above freezing, press
the air conditioning button to run the A/C
compressor. Also it is best to avoid the use of the
recirculation mode except when maximum air
conditioning performance is needed or for short
times to avoid exterior odors.
You may notice a slight change in engine
performance when the air-conditioning compressor
shuts off and turns on again. This is normal.Defogging and Defrosting
Fog on the inside of the windows is a result of
moisture condensing on the cool window glass.
This can be reduced if the climate control system is
used properly. You can use either defog or front
defrost to clear fog or frost from your windshield.
-(Defog):Use this setting to clear the windows
of fog or moisture. This setting will deliver air
to the oor and windshield outlets.
0(Front Defrost):Press the front defrost button
to clear the windshield and side windows of
frost or fog quickly. The system will automatically
control the fan speed if you select defrost from
AUTO mode. If the outside temperature is
40°F (4°C) or warmer, your air conditioning
compressor will automatically run to help
dehumidify the air and dry the windshield. Do not
drive the vehicle until all the windows are clear.
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Rear Window Defogger
If your vehicle has the rear window defogger a
warming grid is used to remove fog from the
rear window.
<(Rear):Press this button to turn the rear
window defogger on or off.
An indicator light in the button will come on
to let you know that the rear window defogger
is activated.
The rear window defogger will turn off
approximately 10 minutes after the button is
pressed. If you need additional warming time,
press the button again.
If your vehicle has heated mirrors, they will come
on when this button is pressed.
Notice:Do not use a razor blade or sharp
object to clear the inside rear window. Do not
adhere anything to the defogger grid lines
in the rear glass. These actions may damage
the rear defogger. Repairs would not be
covered by your warranty.
Outlet Adjustment
Use the air outlets located in the center and on the
side of the instrument panel to direct the airow.
Operation Tips

Keep the hood and front air inlets free of ice,
snow, or any other obstruction, such as
leaves. The heater and defroster will work
better, reducing the chance of fogging
the inside of your windows.
When you enter a vehicle in cold weather, set
the fan speed to maximum airow for a few
moments before driving. This helps clear
the intake ducts of snow and moisture, and
reduces the chance of fogging the inside
of your windows.
Keep the air path under the front seats clear
of objects. This helps air to circulate
throughout your vehicle.
Adding outside equipment to the front of the
vehicle, such as hood-air deectors, may
affect the performance of the heating and air
conditioning system. Check with your
dealer before adding equipment to the outside
of your vehicle.
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6(Floor):When oor mode is selected, the rear
system will distribute air from the second seat
side oor outlets and the third seat oor outlet.
If your vehicle has the rear seat audio system, the
lower buttons are used to adjust the rear seat
climate control system. The temperature of the air
coming through the rear outlets is determined
by the front passenger’s temperature setting.P(On/Off):Press this button to turn the rear
climate controls on or off.
z9 y(Fan):Press this button to adjust the
fan speed.
z\y(Mode):Press this button to change the
direction of airow (panel, bi-level or oor) to
the rear seat area.
The rear control will only turn on if the front is on
and not in defrost mode.
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Driving with a Trailer
{CAUTION:
If you have a rear-most window open and
you pull a trailer with your vehicle, carbon
monoxide (CO) could come into your
vehicle. You can not see or smell CO. It can
cause unconsciousness or death. See
Engine Exhaust on page 131. To maximize
your safety when towing a trailer:
Have your exhaust system inspected
for leaks, and make necessary repairs
before starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with
the fan on any speed. This will bring
fresh, outside air into your vehicle.
CAUTION: (Continued)
CAUTION: (Continued)
Do not use the climate control setting for
maximum air because it only recirculates
the air inside your vehicle. SeeDual
Climate Control System on page 186.
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint
yourself with the feel of handling and braking with
the added weight of the trailer. And always
keep in mind that the vehicle you are driving is
now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connection,
lamps, tires and mirror adjustment. If the trailer
has electric brakes, start your vehicle and
trailer moving and then apply the trailer brake
controller by hand to be sure the brakes are
working. This lets you check your electrical
connection at the same time.
370

Service........................................................ 380
Accessories and Modications................... 380
California Proposition 65 Warning.............. 381
Doing Your Own Service Work.................. 381
Adding Equipment to the Outside of
Your Vehicle.......................................... 382
Fuel............................................................. 382
Gasoline Octane........................................ 382
Gasoline Specications.............................. 383
California Fuel........................................... 383
Additives................................................... 383
Fuels in Foreign Countries........................ 384
Filling the Tank......................................... 385
Filling a Portable Fuel Container............... 387
Checking Things Under the Hood.............. 388
Hood Release........................................... 388
Engine Compartment Overview.................. 390
Engine Oil................................................. 394
Engine Oil Life System.............................. 398
Engine Air Cleaner/Filter............................ 400
Automatic Transmission Fluid.................... 401
Engine Coolant.......................................... 405Radiator Pressure Cap.............................. 408
Engine Overheating................................... 408
Cooling System......................................... 411
Engine Fan Noise..................................... 416
Power Steering Fluid ................................. 417
Windshield Washer Fluid........................... 418
Brakes...................................................... 419
Battery...................................................... 422
Jump Starting............................................ 423
Rear Axle.................................................... 428
Four-Wheel Drive........................................ 428
Front Axle................................................... 429
Bulb Replacement....................................... 430
Halogen Bulbs........................................... 430
Headlamps................................................ 431
Front Turn Signal, Sidemarker and
Parking Lamps....................................... 432
Taillamps, Turn Signal, and Stoplamps...... 432
Back-Up Lamps......................................... 434
License Plate Lamp................................... 435
Replacement Bulbs................................... 435
Section 5 Service and Appearance Care
377

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 (N) 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 windows 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 does not 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 is 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 are parked. If you still have the
warning, turn off the engine and get everyone out of
the vehicle until it cools down.
You may decide not to lift the hood but to get
service help right away.
410

Cooling System
When you decide it is safe to lift the hood, here is
what you will see:
A. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine FanA. Coolant Recovery Tank
B. Radiator Pressure Cap
C. Engine Fan
If the coolant inside the coolant recovery tank is
boiling, do not do anything else until it cools down.
The vehicle should be parked on a level surface.
4.2L L6 Engine
5.3L V8 Engine
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The coolant level should
be at least up to the
FULL COLD mark. If it
is not, 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 does not, 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 could 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.
412

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