2009 GMC ENVOY ECO mode

StabiliTrak Off
In this mode, both stability control and part of the traction
control system are disabled. The vehicle will still have
brake-traction control, but will not be able to use the
engine speed management system. System noises may
be heard as a result of the brake-traction control coming
on. If the controller detects excessive wheel spin in this
mode, the StabiliTrak indicator light may blink and the
STABILITRAK ACTIVE message may be displayed
to warn the driver that damage may occur to the
transfer case.
It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn
the system off if the vehicle is stuck in sand, mud, ice orsnow, and you may want to “rock” the vehicle in an
attempt to free it. It may also be necessary to turn off the
system when driving in extreme off-road conditions
where high wheel spin is required. SeeIf Your Vehicle
is Stuck in Sand, Mud, Ice, or Snow on page 4-30
for more information.
When the transfer case is in 4LO, the stability system is
automatically disabled. The StabiliTrak light will come
on and the STABILITRAK OFF message will appear on
the DIC. The StabiliTrak system cannot be turned on
until the vehicle is switched to 2HI, 4HI, or 4AWD.
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).
SolidTraction
Control OffSolid Off Traction Control Off Mode
Solid StabiliTrak Off Solid OffStabiliTrak Off Mode (StabiliTrak
indicator light will ash when system
rst enters this mode).
4-8

Electronically Controlled Air
Suspension System
With this feature, an electronically controlled air
suspension system automatically keeps the vehicle level
as it is loaded and unloaded. 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.
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.
The compressor may be heard while it is operating when
the vehicle is being loaded, 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.
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 the Vehicle on page 4-31.
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, the
vehicle should be serviced as soon as possible.
4-45

Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit for air pressure.
Light Truck (LT-Metric) Tire
:A tire used on
light duty trucks and some multipurpose passenger
vehicles.
Load Index
:An assigned number ranging from
1 to 279 that corresponds to the load carrying
capacity of a tire.
Maximum Ination Pressure
:The maximum air
pressure to which a cold tire can be inated.
The maximum air pressure is molded onto the
sidewall.
Maximum Load Rating
:The load rating for a tire
at the maximum permissible ination pressure
for that tire.
Maximum Loaded Vehicle Weight
:The sum of
curb weight, accessory weight, vehicle capacity
weight, and production options weight.
Normal Occupant Weight
:The number of
occupants a vehicle is designed to seat multiplied
by 150 lbs (68 kg). SeeLoading the Vehicle on
page 4-31.Occupant Distribution
:Designated seating
positions.
Outward Facing Sidewall
:The side of an
asymmetrical tire that has a particular side
that faces outward when mounted on a vehicle.
The side of the tire that contains a whitewall,
bears white lettering, or bears manufacturer, brand,
and/or model name molding that is higher or deeper
than the same moldings on the other sidewall of
the tire.
Passenger (P-Metric) Tire
:A tire used on
passenger cars and some light duty trucks and
multipurpose vehicles.
Recommended Ination Pressure
:Vehicle
manufacturer’s recommended tire ination
pressure as shown on the tire placard. See
Inflation - Tire Pressure on page 5-60andLoading
the Vehicle on page 4-31.
Radial Ply Tire
:A pneumatic tire in which the
ply cords that extend to the beads are laid at
90 degrees to the centerline of the tread.
Rim
:A metal support for a tire and upon which
the tire beads are seated.
5-58

Current and Past Model Order Forms
Technical Service Bulletins and Manuals are available
for current and past model GM vehicles. To request
an order form, specify year and model name of
the vehicle.
ORDER TOLL FREE: 1-800-551-4123
Monday-Friday 8:00 AM - 6:00 PM
Eastern Time
For Credit Card Orders Only
(VISA-MasterCard-Discover), visit Helm, Inc.
on the World Wide Web at: helminc.com
Or you can write to:
Helm, Incorporated
P.O. Box 07130
Detroit, MI 48207
Prices are subject to change without notice and without
incurring obligation. Allow ample time for delivery.
Note to Canadian Customers: All listed prices are
quoted in U.S. funds. Canadian residents are to make
checks payable in U.S. funds.
Vehicle Data Recording and
Privacy
Your GM vehicle has a number of sophisticated
computers that record information about the vehicle’s
performance and how it is driven. For example,
your vehicle uses computer modules to monitor and
control engine and transmission performance, to monitor
the conditions for airbag deployment and deploy
airbags in a crash and, if so equipped, to provide
antilock braking to help the driver control the vehicle.
These modules may store data to help your
dealer/retailer technician service your vehicle. Some
modules may also store data about how you operate the
vehicle, such as rate of fuel consumption or average
speed. These modules may also retain the owner’s
personal preferences, such as radio pre-sets, seat
positions, and temperature settings.
7-16