service GMC ENVOY DENALI 2007 Workshop Manual

Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic.
This is a mistake. The brakes may not have time to
cool between hard stops. The brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic
following distances, you will eliminate a lot of
unnecessary braking. That means better braking
and longer brake life.
If your vehicle’s engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the engine stops, you will still have
some power brake assist. But you will use it
when you brake. Once the power assist is used
up, it may take longer to stop and the brake pedal
will be harder to push.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 380.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system that
will help prevent a braking skid.
When you start your engine and begin to drive
away, ABS will check itself. You may hear a
momentary motor or clicking noise while this test
is going on. This is normal.
If there is a problem
with ABS, this warning
light will stay on.
SeeAnti-Lock Brake
System Warning
Light on page 207.
Along with ABS, your vehicle has a Dynamic Rear
Proportioning (DRP) system. If there is a DRP
problem, both the brake and ABS warning lights will
come on accompanied by a 10-second chime.
The lights and chime will come on each time the
ignition is turned on until the problem is repaired.
See your dealer for service.
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The following chart describes the StabiliTrak®system events and the corresponding messages and lights
that will be displayed on the instrument panel cluster.
Vehicles with a DIC Vehicles without a DIC Event
StabiliTrak
®
Indicator LightDIC MessageStabiliTrak
®
Indicator LightStabiliTrak
®
Service Light—
Off None Off OffStabiliTrak
®On mode
(System is fully enabled, but
is not actively controlling
vehicle stability).
Solid Traction Control Off Solid OffTraction Control
Off Mode
Solid StabiliTrak
®Off Solid OffStabiliTrak
®Off Mode
(StabiliTrak®indicator light
will ash when system rst
enters this mode).
Blinking StabiliTrak
®Active Blinking OffStabiliTrak
®system activates
using engine speed
management, brake traction
control, and/or stability
control.
Solid Service StabiliTrak
®Solid SolidStabiliTrak
®system is
disabled due to a
system fault.
SolidStabiliTrak
®
Not ReadySolid OffStabiliTrak
®system is
disabled due to a failure
to initialize.
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Notice:If the StabiliTrak®light comes on
due to heavy braking and/or because the
traction control system has been continuously
active, do not allow the wheel(s) of one axle to
spin excessively. If you do, you may be causing
damage to the transfer case. This could lead to
costly repairs not covered by your warranty.
Notice:If you allow the wheel(s) of one axle
to spin excessively while the StabiliTrak
®,
ABS and brake warning lights and the
SERVICE STABILITRAK message are
displayed, you could damage the transfer
case. The repairs would not be covered by your
warranty. Reduce engine power and do not
spin the wheel(s) excessively while these lights
and this message are displayed.
StabiliTrak
®may activate on dry or rough roads or
under conditions such as heavy acceleration
while turning or abrupt upshifts/downshifts of the
transmission. When this happens, you may
notice a reduction in acceleration, or may hear a
noise or vibration. This is normal.If your vehicle is in cruise control when the system
activates, the StabiliTrak
®light will blink, and
the cruise control will automatically disengage.
When road conditions allow, you may re-engage
the cruise control. SeeCruise Control on
page 176.
StabiliTrak
®will turn off automatically if a problem
is detected in the system. The StabiliTrak®
light will come on and SERVICE STABILITRAK
will be displayed on the DIC. For vehicles without a
DIC, the StabiliTrak
®light and the StabiliTrak®
service light will both come on. If the SERVICE
STABILITRAK message (or StabiliTrak®service
light) does not clear itself after restarting the
vehicle, you should see your dealer for service.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modications on page 380for more information.
313

Off-Road Driving
This off-road guide is for vehicles that have
four-wheel drive. Also, seeBraking on page 306.If
your vehicle does not have four-wheel drive, you
should not drive off-road unless you are on a level,
solid surface.
Off-road driving can be great fun. But it does have
some denite hazards. The greatest of these is
the terrain itself.
“Off-roading” means you have left the great North
American road system behind. Traffic lanes
are not marked. Curves are not banked. There
are no road signs. Surfaces can be slippery, rough,
uphill, or downhill. In short, you have gone right
back to nature.
Off-road driving involves some new skills. And that
is why it is very important that you read this guide.
You will nd many driving tips and suggestions.
These will help make your off-road driving safer and
more enjoyable.
Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary
maintenance and service work done. Check to
make sure all underbody shields, if the vehicle has
them, are properly attached.
Be sure you read all the information about your
four-wheel-drive vehicle in this manual.
Is there enough fuel? Is the spare tire fully inated?
Are the uid levels up where they should be? What
are the local laws that apply to off-roading where
you will be driving? If you do not know, you should
check with law enforcement people in the area. Will
you be on someone’s private land? If so, be sure to
get the necessary permission.
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If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on the ignition
system and your vehicle can stall. Stalling can also
occur if you get the tailpipe under water. And,
as long as the tailpipe is under water, you will
never be able to start the engine. When you go
through water, remember that when the brakes get
wet, it may take you longer to stop.
{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your
vehicle downstream and you and your
passengers could drown. If it is only
shallow water, it can still wash away the
ground from under your tires, and you
could lose traction and roll the vehicle
over. Do not drive through rushing water.
SeeDriving in Rain and on Wet Roads on page 335
for more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on
the underbody, chassis, or under the hood.
These accumulations can be a re hazard.
After operation in mud or sand, have the brake
linings cleaned and checked. These substances
can cause glazing and uneven braking. Check the
body structure, steering, suspension, wheels, tires,
and exhaust system for damage. Also, check the
fuel lines and cooling system for any leakage.
Your vehicle will require more frequent service
due to off-road use. Refer to the Maintenance
Schedule for additional information.
333

Before changing lanes, check your mirrors.
Then use your turn signal.
Just before you leave the lane, glance quickly
over your shoulder to make sure there is not
another vehicle in your blind spot.
Once you are moving on the freeway, make
certain you allow a reasonable following distance.
Expect to move slightly slower at night.
When you want to leave the freeway, move to the
proper lane well in advance. If you miss your
exit, do not, under any circumstances, stop and
back up. Drive on to the next exit.
The exit ramp can be curved, sometimes quite
sharply. The exit speed is usually posted.
Reduce your speed according to your
speedometer, not to your sense of motion.
After driving for any distance at higher speeds,
you may tend to think you are going slower than
you actually are.Before Leaving on a Long Trip
Make sure you are ready. Try to be well rested.
If you must start when you are not fresh — such as
after a day’s work — do not plan to make too
many miles that rst part of the journey. Wear
comfortable clothing and shoes you can easily
drive in.
Is your vehicle ready for a long trip? If you keep it
serviced and maintained, it is ready to go. If it
needs service, have it done before starting out.
Of course, you will nd experienced and able
service experts in GM dealerships all across
North America. They will be ready and willing to
help if you need it.
340

Here are some things you can check before a trip:
Windshield Washer Fluid:Is the reservoir
full? Are all windows clean inside and outside?
Wiper Blades:Are they in good shape?
Fuel, Engine Oil, Other Fluids:Have you
checked all levels?
Lamps:Are they all working? Are the lenses
clean?
Tires:They are vitally important to a safe,
trouble-free trip. Is the tread good enough
for long-distance driving? Are the tires
all inated to the recommended pressure?
Weather Forecasts:What is the weather
outlook along your route? Should you
delay your trip a short time to avoid a major
storm system?
Maps:Do you have up-to-date maps?
Highway Hypnosis
Is there actually such a condition as highway
hypnosis? Or is it just plain falling asleep at the
wheel? Call it highway hypnosis, lack of
awareness, or whatever.
There is something about an easy stretch of road
with the same scenery, along with the hum of the
tires on the road, the drone of the engine, and the
rush of the wind against the vehicle that can make
you sleepy. Do not let it happen to you! If it does,
your vehicle can leave the road in less than a
second, and you could crash and be injured.
What can you do about highway hypnosis?
First, be aware that it can happen.
Then here are some tips:
Make sure your vehicle is well ventilated, with
a comfortably cool interior.
Keep your eyes moving. Scan the road ahead
and to the sides. Check your mirrors and your
instruments frequently.
If you get sleepy, pull off the road into a rest,
service, or parking area and take a nap, get
some exercise, or both. For safety, treat
drowsiness on the highway as an emergency.
341

If you put things inside your vehicle — like
suitcases, tools, packages, or anything
else — they will go as fast as the vehicle goes.
If you have to stop or turn quickly, or if there is a
crash, they will keep going.
{CAUTION:
Things you put inside your vehicle can
strike and injure people in a sudden stop
or turn, or in a crash.
Put things in the cargo area of your
vehicle. Try to spread the weight
evenly.
Never stack heavier things, like
suitcases, inside the vehicle so that
some of them are above the tops of
the seats.
Do not leave an unsecured child
restraint in your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
Do not leave a seat folded down
unless you need to.There is also important loading information for
off-road driving in this manual. See “Loading Your
Vehicle for Off-Road Driving” underOff-Road
Driving on page 319.
Adding a Snow Plow or Similar
Equipment
Your vehicle was neither designed nor intended
for a snow plow.
Notice:Adding a snow plow or similar
equipment to your vehicle can damage it, and
the repairs would not be covered by warranty.
Do not install a snow plow or similar
equipment on your vehicle.
Towing
Towing Your Vehicle
Consult your dealer or a professional towing
service if you need to have your disabled vehicle
towed. SeeRoadside Assistance Program on
page 532.
354

Overload Protection
The air suspension system is equipped with
overload protection. Overload protection is
designed to protect the air suspension system,
and it is an indicator to the driver that the vehicle
is overloaded. When the overload protection
mode is on, it will not allow damage to the
air compressor. However, do not overload the
vehicle. SeeLoading Your Vehicle on page 349.
If the suspension remains at a low height, the rear
axle load has exceeded GAWR (Gross Axle
Weight Rating). When the overload protection
mode is activated, the compressor operates
for about 30 seconds to one minute without raising
the vehicle depending on the amount of overload.
This will continue each time the ignition is
turned on until the rear axle load is reduced
below GAWR.
Indicator Light
The indicator light on the inator switch in the rear
passenger compartment also serves as an
indicator for internal system error. If the indicator
light is ashing without the load leveling function
or the inator being active, turn off the ignition.
The next day turn on the ignition and check
the indicator light. The vehicle can be driven with
the light ashing, but if it is you should have
the vehicle serviced as soon as possible.
361

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the
chocks.
4. Stop and have someone pick up and store
the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid (don’t overll), engine
oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in
this manual, and the Index will help you nd them
quickly. If you’re trailering, it’s a good idea to
review these sections before you start your trip.
Check periodically to see that all hitch nuts
and bolts are tight.
374