2007 GMC ENVOY suspension

Your Driving, the Road, and
Your Vehicle............................................ 302
Defensive Driving...................................... 302
Drunken Driving........................................ 303
Control of a Vehicle.................................. 306
Braking...................................................... 306
Anti-Lock Brake System (ABS).................. 307
Braking in Emergencies............................. 309
Locking Rear Axle..................................... 309
StabiliTrak
®System................................... 309
Steering.................................................... 314
Off-Road Recovery.................................... 316
Passing..................................................... 316
Loss of Control.......................................... 318
Off-Road Driving........................................ 319
Driving at Night......................................... 334
Driving in Rain and on Wet Roads............ 335
City Driving............................................... 338Freeway Driving........................................ 339
Before Leaving on a Long Trip.................. 340
Highway Hypnosis..................................... 341
Hill and Mountain Roads........................... 342
Winter Driving........................................... 344
If Your Vehicle is Stuck in Sand, Mud,
Ice, or Snow.......................................... 348
Rocking Your Vehicle to Get It Out........... 348
Loading Your Vehicle................................ 349
Adding a Snow Plow or Similar
Equipment.............................................. 354
Towing........................................................ 354
Towing Your Vehicle ................................. 354
Recreational Vehicle Towing...................... 355
Electronically Controlled Air Suspension
System.................................................. 360
Towing a Trailer........................................ 362
Section 4 Driving Your Vehicle
301

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

Item Description Total
AVehicle Capacity
Weight for Example 3=1,000 lbs (453 kg)
BSubtract
Occupant Weight
200 lbs (91 kg)×5=1,000 lbs (453 kg)
CAvailable Cargo
Weight=0 lbs (0 kg)
Refer to your vehicle’s tire and loading information
label for specic information about your vehicle’s
capacity weight and seating positions. The
combined weight of the driver, passengers,
and cargo should never exceed your vehicle’s
capacity weight.Your vehicle may have an electronically controlled
air suspension system that automatically keeps
your vehicle level as you load and unload your
vehicle. SeeElectronically Controlled Air
Suspension System on page 360for additional
information.
Certication/Tire Label
A vehicle specic Certication/Tire label is found
on the rear edge of the driver’s door. The label
shows the size of your vehicle’s original tires
and the ination pressures needed to obtain
the gross weight capacity of your vehicle.
Example 3
352

This is called Gross Vehicle Weight Rating
(GVWR). The GVWR includes the weight of the
vehicle, all occupants, fuel, cargo, and trailer
tongue weight, if pulling a trailer.
The Certication/Tire label also tells you the
maximum weights for the front and rear axles,
called Gross Axle Weight Rating (GAWR). To nd
out the actual loads on your front and rear axles,
you need to go to a weigh station and weigh your
vehicle. Your dealer can help you with this. Be sure
to spread out your load equally on both sides of the
centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
And, if you do have a heavy load, you should
spread it out.
Similar appearing vehicles may have different
GVWRs and capacity weights. Please note your
vehicle’s Certication/Tire label or consult
your dealer for additional details.
{CAUTION:
Do not load your vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do,
parts on your vehicle can break, and it
can change the way your vehicle handles.
These could cause you to lose control
and crash. Also, overloading can shorten
the life of your vehicle.
Using heavier suspension components to get
added durability might not change your vehicle’s
weight ratings. Ask your dealer to help you
load your vehicle the right way.
Notice:Overloading your vehicle may cause
damage. Repairs would not be covered by your
warranty. Do not overload your vehicle.
353

Electronically Controlled Air
Suspension System
Your vehicle may be equipped with an electronically
controlled air suspension system that automatically
keeps your vehicle level as you load and unload.
The system includes a compressor, two height
sensors and two air springs supporting the
rear axle.
The system also has an internal clock to prevent
overheating if the inator is used for prolonged
periods. If the system overheats, all leveling
function stops until the system cools down.
During this time, the indicator light on the air
inator switch will be ashing.The ignition has to be on for the system to inate,
in order to raise the vehicle to the standard ride
height after loading. The system can lower
the vehicle to the standard ride height after
unloading with the ignition on and also for up to
30 minutes after the ignition has been turned off.
You may hear the compressor operating when you
load your vehicle, and periodically as the system
adjusts the vehicle to the standard ride height.
Load leveling will not function normally with the
inator hose attached to the inator outlet. Remove
the inator hose from the outlet during loading
and unloading.
If the vehicle is parked for an extended period of
time, some bleed down of the suspension is
normal. Upon starting the vehicle, proper height
will be achieved.
360

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

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven. It
could fail suddenly and cause a crash. If
you have to replace a wheel, use a new
GM original equipment wheel.
Tire Chains
{CAUTION:
Do not use tire chains. There is not
enough clearance. Tire chains used on a
vehicle without the proper amount of
clearance can cause damage to the
brakes, suspension, or other vehicle
parts. The area damaged by the tire
chains could cause you to lose control of
your vehicle and you or others may be
injured in a crash. Use another type of
traction device only if its manufacturer
recommends it for use on your vehicle
and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to
your vehicle, drive slowly, re-adjust or
remove the device if it is contacting your
vehicle, and do not spin your wheels. If
you do nd traction devices that will t,
install them on the rear tires.
461

4. Press and release the switch to turn the air
inator on. The indicator light will remain on
when the inator is running.
The system has an internal clock to prevent
the system from overheating. The system
will allow about ve minutes of running time,
then the compressor will stop. The indicator
light will then begin to ash. When the indicator
is off, the inator can be started again by
pressing the switch. If the compressor is still
hot, it may only run for a short time before
shutting off again.
5. Press and release the switch to turn the
inator off.Place the inator kit tools in the pouch and store it
in its proper location. Remove the inator hose
from the outlet during loading and unloading. Load
leveling will not function with the inator hose
attached to the inator outlet. SeeElectronically
Controlled Air Suspension System on page 360for
more information.
To reinstall the cover, line up the tabs at the back
of the cover, put it in place and latch the tabs.
A continuous ashing indicator light may also
indicate a malfunction in the air suspension
system. SeeElectronically Controlled Air
Suspension System on page 360for more
information.
463