automatic transmission CHEVROLET EXPRESS 2012 User Guide

Black plate (31,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Driving and Operating 9-31
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 9-8.
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 9-32.
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 reduction in
acceleration occurs, it 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 10-2.
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.

Black plate (34,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
9-34 Driving and Operating
Using Cruise Control on Hills
How well cruise control works on
hills depends on the vehicle speed,
load, and the steepness of the hills.
When going up steep hills, you
might have to step on the
accelerator pedal to maintain your
speed.
While going downhill:
.Vehicles with a 4-speed
automatic transmission may
need to have the brakes applied
or the transmission shifted to a
lower gear to help maintain
driver selected speed.
.Vehicles with a 6-speed
automatic transmission have
Cruise Grade Braking to help
maintain driver selected speed.Cruise Grade Braking is enabled
when the vehicle is started and
cruise control is active. It is not
enabled in Range Selection Mode.
It assists in maintaining driver
selected speed when driving on
downhill grades by using the engine
and transmission to slow the
vehicle.
To disable and enable Cruise Grade
Braking for the current ignition key
cycle, press and hold the Tow/Haul
button for three seconds. A DIC
message displays. See
Transmission Messages on
page 5-36.
When the brakes are manually
applied the cruise control is
disengaged.
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press[.
.Shift the transmission to
N (Neutral).
.To turn off cruise control,
press
I.
Erasing Speed Memory
The cruise control set speed is
erased from memory if
Iis
pressed or if the vehicle is
turned off.

Black plate (47,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Driving and Operating 9-47
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule on
page 11-3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
well—or even at all. The driver
and passengers could be
seriously injured. The vehicle may
also be damaged; the resulting
repairs would not be covered by
the vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
{Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” following.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.

Black plate (1,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-2
Accessories and Modifications . . . . . . . . . . . . . . . 10-2
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil Life System . . . . . . 10-8
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . 10-9
Engine Air Cleaner/Filter . . . . 10-12
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-14
Engine Overheating . . . . . . . . 10-18
Engine Fan . . . . . . . . . . . . . . . . . 10-20
Power Steering Fluid . . . . . . . 10-20
Washer Fluid . . . . . . . . . . . . . . . 10-21 Brakes . . . . . . . . . . . . . . . . . . . . . 10-22
Brake Fluid . . . . . . . . . . . . . . . . . 10-23
Battery . . . . . . . . . . . . . . . . . . . . . 10-24
Rear Axle . . . . . . . . . . . . . . . . . . 10-25
Noise Control System . . . . . . 10-25
Starter Switch Check . . . . . . . 10-26
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-27
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-27
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-27
Wiper Blade Replacement . . . . . . . . . . . . . . 10-28
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-28
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-29
Halogen Bulbs . . . . . . . . . . . . . . 10-29
Headlamps . . . . . . . . . . . . . . . . . 10-29
Front Turn Signal,Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-31
Taillamps . . . . . . . . . . . . . . . . . . . 10-31 Center High-Mounted
Stoplamp (CHMSL) . . . . . . . 10-32
License Plate Lamp . . . . . . . . 10-33
Replacement Bulbs . . . . . . . . . 10-33
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-34
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-35
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-35
Floor Console Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-39
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-41
All-Season Tires . . . . . . . . . . . . 10-42
Winter Tires . . . . . . . . . . . . . . . . 10-42
All-Terrain Tires . . . . . . . . . . . . 10-43
Tire Sidewall Labeling . . . . . . 10-43
Tire Designations . . . . . . . . . . . 10-46
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-47
Tire Pressure . . . . . . . . . . . . . . . 10-50
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-51
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-52

Black plate (6,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-6 Vehicle Care
1.Battery on page 10-24.
2. Radiator Pressure Cap. See Cooling System on page 10-14.
3. Coolant Recovery Tank. See Cooling System on page 10-14.
4. Automatic Transmission Fluid Dipstick. See “Checking the
Fluid Level” underAutomatic
Transmission Fluid on
page 10-9.
5. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-6.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-6.
7. Engine Air Cleaner/Filter on
page 10-12.
8. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10-20.
9. Brake Master Cylinder Reservoir. See Brake Fluid on
page 10-23. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-21.
Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-8.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the vehicle
must be on level ground. The
engine oil dipstick handle is a loop.
SeeEngine Compartment Overview
on page 10-5 for the location of the
engine oil dipstick.
Obtaining an accurate oil level
reading is essential:
1. If the engine has been running recently, turn off the engine and
allow several minutes for the oil
to drain back into the oil pan.
Checking the oil level too soon
after engine shutoff will not
provide an accurate oil level
reading.

Black plate (9,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-9
For the oil life system to work
properly, the system must be reset
every time the oil is changed.
When the system has calculated
that oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE
OIL SOON message comes on. See
Engine Oil Messages on page 5-31.
Change the oil as soon as possible
within the next 1 000 km (600 mi).
It is possible that, if driving under
the best conditions, the oil life
system might indicate that an oil
change is not necessary for up to a
year. The engine oil and filter must
be changed at least once a year
and, at this time, the system must
be reset. Your dealer has trained
service people who will perform this
work and reset the system. It is also
important to check the oil regularly
over the course of an oil drain
interval and keep it at the proper
level.If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. To reset the
system:
1. Turn the ignition key to ON/RUN
with the engine off.
2. Fully press and release the accelerator pedal slowly three
times within five seconds.
3. Turn the key to LOCK/OFF.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not reset. Repeat the
procedure.
Automatic Transmission
Fluid
When to Check and Change
Automatic Transmission Fluid
It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. If a small leak is
suspected, use the following
procedures to check the fluid level.
However, if there is a large leak, it
may be necessary to have the
vehicle towed to a dealer and have
it repaired before driving the vehicle
further.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule on page 11-3, and be sure
to use the transmission fluid listed in
Recommended Fluids and
Lubricants on page 11-11.

Black plate (10,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-10 Vehicle Care
How to Check Automatic
Transmission Fluid
Because this operation can be
difficult, it is recommended to have
this check done at your dealer,
which can monitor the transmission
temperature. The transmission fluid
level increases with temperature. To
obtain a highly accurate fluid level
check, the transmission temperature
must be measured.
If it is decided to check the fluid
level, be sure to follow all the
instructions here, or a false reading
on the dipstick may occur.
{Caution
Too much or too little fluid can
damage the transmission. Too
much can mean that some of the
fluid could come out and fall on
hot engine parts or exhaust
system parts, starting a fire. Too
little fluid could cause the(Continued)
Caution (Continued)
transmission to overheat. Be sure
to get an accurate reading if
checking the transmission fluid.
Wait at least 30 minutes with the
engine off, before checking the
transmission fluid level if the vehicle
has been driven:
.In hot weather, when outside
temperatures are above 32°C
(90°F).
.The vehicle is heavily loaded.
.At high speed for quite a while in
hot weather.
.In heavy traffic and hot weather.
.While pulling a trailer.
After driving under these conditions,
a hot check can be performed. The
fluid should be hot, which is 71°C to
93°C (160°F to 200°F). A cold fluid level check can be
performed after the vehicle has
been sitting for eight hours or more
with the engine off, but this is used
only as a reference. Let the engine
run at idle for five minutes if the
outside temperature is between
15°C to 32°C (60°F to 90°F). Should
the fluid level be low during this cold
check, the fluid must be checked
warm or hot before adding fluid.
If the outside temperature is colder
than 15°C (60°F) or hotter than
32°C (90°F), a cold check cannot be
performed.
A warm fluid level check can be
performed by driving the vehicle
under lightly loaded conditions and
outside temperatures between 10°C
to 27°C (50°F to 80°F). The vehicle
should be driven for at least 24 km
(15 mi) before performing a warm
check. Checking the fluid warm or
hot will give a more accurate
reading of the fluid level than a cold
check.

Black plate (12,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-12 Vehicle Care
How to Add Automatic
Transmission Fluid
Refer toRecommended Fluids and
Lubricants on page 11-11 to
determine what kind of transmission
fluid to use.
1. WARM Range
2. HOT Range
Using a funnel, add fluid down the
transmission dipstick tube only after
checking the transmission fluid
while it is warm or hot. A cold check
is used only as a reference. If the
fluid level is low, add only enough of
the proper fluid to bring the level up
to the middle of the WARM (1) or
HOT (2) range depending on the
ambient temperature and prior
driving conditions. Refer to “How to
Check Automatic Transmission Fluid”
earlier in this section for
instructions on driving to achieve
warm or hot transmission fluid.
It does not take much fluid,
generally less than 0.5 L (1 pt). Do
not overfill.
{Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
not be covered by the vehicle
warranty. Always use the
automatic transmission fluid listed
in Recommended Fluids and
Lubricants on page 11-11.
.After adding fluid, recheck the
fluid level as described under
“How to Check Automatic
Transmission Fluid,” earlier in
this section.
.When the correct fluid level is
obtained, push the dipstick back
in all the way; then flip the
handle down to lock the dipstick
in place.
Engine Air Cleaner/Filter
The engine air cleaner/filter is near
the center of the engine
compartment. See Engine
Compartment Overview on
page 10-5.

Black plate (27,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-27
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move. 3. With the engine off, turn the
ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
While parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.

Black plate (47,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-47
(3) Aspect Ratio:A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item 3 of the light truck
(LT-Metric) tire illustration, it
would mean that the tire's
sidewall is 75 percent as high as
it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Load Range
:Load Range. (7) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load. This
does not apply to Goodyear
LT225/75R16 G949 RSA and
Goodyear LT225/75R16 G933
RSD commercial truck tires; see
the dual tire and single tire
maximum load and load range
letter designations on the tire
sidewall.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.