traction control CHEVROLET EXPRESS CARGO VAN 2012 1.G User Guide

Black plate (11,1)Chevrolet Express Owner Manual - 2012
Driving and Operating 9-11
Rocking the Vehicle to Get
it Out
Turn the steering wheel left and
right to clear the area around the
front wheels. Turn off any traction or
stability system. Shift back and forth
between R (Reverse) and a forward
gear, spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears.
Release the accelerator pedal while
shifting, and press lightly on the
accelerator pedal when the
transmission is in gear. Slowly
spinning the wheels in the forward
and reverse directions causes a
rocking motion that could free the
vehicle. If that does not get the
vehicle out after a few tries, it might
need to be towed out. If the vehicle
does need to be towed out, see
Towing the Vehicle on page 10‑90.
Vehicle Load Limits
It is very important to know how
much weight the vehicle can
carry. This weight is called the
vehicle capacity weight and
includes the weight of all
occupants, cargo, and all
nonfactory-installed options.
Two labels on the vehicle show
how much weight it was
designed to carry, the Tire and
Loading Information label and
the Certification/Tire label.{WARNING
Do not load the vehicle any
heavier than the Gross
Vehicle Weight Rating
(GVWR), or either the
maximum front or rear Gross
Axle Weight Rating (GAWR).
This can cause systems to
break and change the way the
vehicle handles. This could
cause loss of control and a
crash. Overloading can also
shorten the life of the vehicle.

Black plate (31,1)Chevrolet Express Owner Manual - 2012
Driving and Operating 9-31
Manual Mode
Range Selection Mode
The vehicle may have a Range
Selection Mode. The Range
Selection Mode helps control the
vehicle's transmission and vehicle
speed while driving down hill or
towing a trailer by letting you select
a desired range of gears.
To use this feature, do the following:
1. Move the shift lever toM (Manual Mode).
2. Press the +/− buttons, located
on the steering column shift
lever, to select the desired range
of gears for current driving
conditions. When M (Manual Mode) is selected
a number displays in the DIC next to
the M indicating the current gear.
This number is the highest gear that
can be used. However, the vehicle
can automatically shift to lower
gears as it adjusts to driving
conditions. This means that all
gears below that number are
available. When 5 (Fifth) is selected,
1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle,
but 6 (Sixth) cannot be used until
the +/−
button located on the
steering column lever is used to
change to the gear.
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode on page 9‑32.
While using Range Selection Mode,
Cruise Control and the Tow/Haul
Mode can be used. Notice:
Spinning the tires or
holding the vehicle in one place
on a hill using only the
accelerator pedal may damage
the transmission. The repair will
not be covered by the vehicle
warranty. If you are stuck, do not
spin the tires. When stopping on
a hill, use the brakes to hold the
vehicle in place.Low Traction Mode
Low Traction Mode can assist in
vehicle acceleration when road
conditions are slippery. While the
vehicle is at a stop, select the
second gear range using Range
Selection Mode. This will limit
torque to the wheels after it detects
wheel slip, preventing the tires
from spinning.

Black plate (35,1)Chevrolet Express Owner Manual - 2012
Driving and Operating 9-35
Ride Control Systems
StabiliTrak®System
The vehicle may have a vehicle
stability enhancement system called
StabiliTrak. It is an advanced
computer controlled system that
assists the driver with directional
control of the vehicle in difficult
driving conditions.
StabiliTrak activates when the
computer senses a discrepancy
between the intended path and the
direction the vehicle is actually
traveling. StabiliTrak selectively
applies braking pressure at any one
of the vehicle's brakes to assist the
driver with keeping the vehicle on
the intended path.
When the vehicle is started and
begins to move, the system
performs several diagnostic checks
to insure there are no problems.
The system may be heard or felt
while it is working. This is normal
and does not mean there is a
problem with the vehicle.The system should initialize before
the vehicle reaches 32 km/h
(20 mph). In some cases, it may
take approximately 3.2 km (2 mi) of
driving before the system initializes.
The Traction Control System (TCS)/
StabiliTrak indicator light comes on
the instrument panel cluster when
the system requires service.
When StabiliTrak activates, the
TCS/StabiliTrak indicator light
flashes on the instrument panel.
This also occurs when TCS is
activated.
For more information, see
Traction
Control System (TCS)/StabiliTrak
®
Light on page 5‑26.
For your safety, the system can only
be disabled when the vehicle speed
is less than 32 km/h (20 mph).
Press the StabiliTrak button located
on the instrument panel once to turn
off the Traction Control System
(TCS). The appropriate message is
displayed in the DIC.
Press and hold the StabiliTrak
button for more than five seconds to
turn off StabiliTrak and TCS.

Black plate (36,1)Chevrolet Express Owner Manual - 2012
9-36 Driving and Operating
The StabiliTrak Off light illuminates
and the appropriate messages will
be displayed in the DIC.
To turn on the StabiliTrak system
back on, press the StabiliTrak
button again. StabiliTrak will
automatically turn back on when
the vehicle speed exceeds
32 km/h (20 mph).
When the StabiliTrak system has
been turned off, system noises may
still be heard as a result of the
brake-traction control coming on.
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 or snow,
and you want to“rock”the vehicle to
attempt to free it. See If the Vehicle
Is Stuck on page 9‑10.StabiliTrak System Operation
The StabiliTrak system is normally
on, except when the system is
initializing or has been disabled
with the StabiliTrak button. The
StabiliTrak system will automatically
activate to assist the driver in
maintaining vehicle directional
control in most driving conditions.
When activated, the StabiliTrak
system may reduce engine power to
the wheels and apply braking to
individual wheels as necessary to
assist the driver with vehicle
directional control. If cruise control
is being used when StabiliTrak
activates, the cruise control
automatically disengages. The
cruise control can be re-engaged
when road conditions allow. See
Cruise Control on page 9‑37.
The StabiliTrak system may also
turn off automatically if it determines
that a problem exists with the
system. If the problem does not
clear itself after restarting the
vehicle, see your dealer for service.
Traction Control Operation
TCS is part of the StabiliTrak
system. TCS limits wheel spin by
reducing engine power to the
wheels and by applying brakes to
each individual wheel as necessary.
If the brake-traction control system
activates constantly or if the brakes
have heated up due to high speed
braking, the brake-traction control
will be automatically disabled. The
system will come back on after the
brakes have cooled. This can take
up to two minutes or longer
depending on brake usage.
TCS 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 a reduction
in acceleration may be noticed, or a
noise or vibration may be heard.
This is normal.
Adding non‐dealer accessories can
affect the vehicle's performance.
See Accessories and Modifications
on page 10‑3 for more information.

Black plate (37,1)Chevrolet Express Owner Manual - 2012
Driving and Operating 9-37
Locking Rear Axle
Vehicles with a locking rear axle can
give more traction on snow, mud,
ice, sand, or gravel. It works like a
standard axle most of the time, but
when traction is low, this feature will
allow the rear wheel with the most
traction to move the vehicle.
Cruise Control
{WARNING
Cruise control can be dangerous
where you cannot drive safely at
a steady speed. So, do not use
the cruise control on winding
roads or in heavy traffic.
Cruise control can be dangerous
on slippery roads. On such roads,
fast changes in tire traction can
cause excessive wheel slip, and
you could lose control. Do not use
cruise control on slippery roads.For vehicles with cruise control, a
speed of about 40 km/h (25 mph) or
more can be maintained without
keeping your foot on the
accelerator. Cruise control does
not work at speeds below about
40 km/h (25 mph).
When the brakes are applied,
cruise control is turned off.
If the vehicle has StabiliTrak and the
system begins to limit wheel spin,
cruise control will automatically
disengage. See
StabiliTrak
®System
on page 9‑35. When road conditions
allow the cruise control to be safely
used again, it can be turned
back on.

Black plate (3,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-3
Accessories and
Modifications
Adding non‐dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty.Damage to vehicle components
resulting from modifications or the
installation or use of non‐GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle on
page 3‑35.

Black plate (65,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-65
SeeTire Inspection on page 10‑62
and Tire Rotation on page 10‑62 for
additional information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple conditions
including temperatures, loading
conditions, and inflation pressure
maintenance affect how fast aging
takes place. Tires will typically need
to be replaced due to wear before
they may need to be replaced
due to age. Consult the tire
manufacturer for more information
on when tires should be replaced.
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park
a vehicle that will be stored for at
least a month in a cool, dry, clean
area away from direct sunlight to
slow aging. This area should be
free of grease, gasoline or other
substances that can deteriorate
rubber. Parking for an extended period can
cause flat spots on the tires that
may result in vibrations while
driving. When storing a vehicle for
at least a month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle.
The original equipment tires
installed were designed to meet
General Motors Tire Performance
Criteria Specification (TPC Spec)
system rating. When replacement
tires are needed, GM strongly
recommends buying tires with the
same TPC Spec rating.
GM's exclusive TPC Spec system
considers over a dozen critical
specifications that impact the
overall performance of the
vehicle, including brake system
performance, ride and handling,
traction control, and tire pressure
monitoring performance.
GM's TPC Spec number is molded
onto the tire's sidewall near the tire
size. If the tires have an all‐season
tread design, the TPC Spec number
will be followed by MS for mud and
snow. See
Tire Sidewall Labeling on
page 10‑50 for additional
information.

Black plate (67,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-67
Vehicles that have a tire pressure
monitoring system could give an
inaccurate low‐pressure warning if
non‐TPC Spec rated tires are
installed. SeeTire Pressure Monitor
System on page 10‑58.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle.
See Vehicle Load Limits on
page 9‑11 for the label location and
more information about the Tire and
Loading Information label.Different Size Tires and
Wheels
If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, and electronic stability
control, the performance of these
systems can also be affected.
{WARNING
If different sized wheels are used,
there may not be an acceptable
level of performance and safety if
tires not recommended for those
wheels are selected. This
increases the chance of a crash
and serious injury. Only use GM
specific wheel and tire systems
developed for the vehicle, and
have them properly installed by a
GM certified technician.
See Buying New Tires on
page 10‑65 andAccessories and
Modifications on page 10‑3 for
additional information.

Black plate (68,1)Chevrolet Express Owner Manual - 2012
10-68 Vehicle Care
Uniform Tire Quality
Grading
Quality grades can be found
where applicable on the tire
sidewall between tread shoulder
and maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
The following information relates
to the system developed by the
United States National Highway
Traffic Safety Administration
(NHTSA), which grades tires
by treadwear, traction, and
temperature performance.
This applies only to vehicles
sold in the United States.
The grades are molded on the
sidewalls of most passenger
car tires.The Uniform Tire Quality
Grading (UTQG) system
does not apply to deep tread,
winter-type snow tires,
space-saver, or temporary use
spare tires, tires with nominal
rim diameters of 10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
General Motors passenger cars
and light trucks may vary with
respect to these grades, they
must also conform to federal
safety requirements and
additional General Motors Tire
Performance Criteria (TPC)
standards.
All Passenger Car Tires Must
Conform to Federal Safety
Requirements In Addition To
These Grades.Treadwear
The treadwear grade is a
comparative rating based on the
wear rate of the tire when tested
under controlled conditions on a
specified government test
course. For example, a tire
graded 150 would wear one and
a half (1½) times as well on the
government course as a tire
graded 100. The relative
performance of tires depends
upon the actual conditions of
their use, however, and may
depart significantly from the
norm due to variations in driving
habits, service practices and
differences in road
characteristics and climate.

Black plate (69,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-69
Traction–AA, A, B, C
The traction grades, from
highest to lowest, are AA, A, B,
and C. Those grades represent
the tire's ability to stop on wet
pavement as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C may
have poor traction performance.
Warning: The traction grade
assigned to this tire is based on
straight-ahead braking traction
tests, and does not include
acceleration, cornering,
hydroplaning, or peak traction
characteristics. Temperature
–A, B, C
The temperature grades
are A (the highest), B, and C,
representing the tire's resistance
to the generation of heat and its
ability to dissipate heat when
tested under controlled
conditions on a specified indoor
laboratory test wheel. Sustained
high temperature can cause the
material of the tire to degenerate
and reduce tire life, and
excessive temperature can lead
to sudden tire failure. The grade
C corresponds to a level of
performance which all
passenger car tires must meet
under the Federal Motor Safety
Standard No. 109. Grades B and
A represent higher levels of
performance on the laboratory
test wheel than the minimum
required by law. Warning: The
temperature grade for this tire is
established for a tire that is properly inflated and not
overloaded. Excessive speed,
underinflation, or excessive
loading, either separately or in
combination, can cause heat
buildup and possible tire failure.
Wheel Alignment and Tire
Balance
The tires and wheels were aligned
and balanced at the factory to
provide the longest tire life and best
overall performance. Adjustments to
wheel alignment and tire balancing
will not be necessary on a regular
basis. However, check the
alignment if there is unusual tire
wear or if the vehicle is pulling to
one side or the other. If the vehicle
vibrates when driving on a smooth
road, the tires and wheels might
need to be rebalanced. See your
dealer for proper diagnosis.