engine CHEVROLET EXPRESS CARGO VAN 2015 1.G Repair Manual

Black plate (27,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
Driving and Operating 9-27
Tow/Haul Mode
If equipped, Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling, providing
increased performance, vehicle
control, and transmission cooling
when towing or hauling heavy loads.Turn the Tow/Haul Mode on and off
by pressing the button on the
instrument panel. When Tow/Haul is
on, a light on the instrument cluster
will come on.
See
Tow/Haul Mode Light on
page 5-21.
Also see “Tow/Haul Mode” under
Towing Equipment on page 9-51.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is
only enabled while the Tow/Haul
Mode is selected and the vehicle is
not in the Range Selection Mode.
See “Tow/Haul Mode” listed
previously and Manual Mode on
page 9-26. Tow/Haul Mode Grade
Braking assists in maintaining
desired vehicle speeds when driving
on downhill grades by using the
engine and transmission to slow the
vehicle. To disable or enable Tow/Haul Mode
Grade Braking within the current
ignition key cycle, press and hold
the Tow/Haul button for
three seconds. A DIC message will
be displayed. See
Transmission
Messages on page 5-36.
See Towing Equipment on
page 9-51.
For other forms of grade braking,
see Automatic Transmission on
page 9-22 andCruise Control on
page 9-32.

Black plate (31,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
Driving and Operating 9-31
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 10-3.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 - 2/10/15
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 (39,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
Driving and Operating 9-39
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines”in the
Duramax diesel supplement.
For gasoline engine vehicles, use of
the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S. and Canada, to
help keep the engine clean and
maintain optimum vehicle
performance, we recommend using
TOP TIER Detergent Gasolines.
See www.toptiergas.com for a list of
TOP TIER Detergent Gasolines.
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. See E85 or FlexFuel on
page 9-40.
Use regular unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 87 or
higher. Do not use gasoline with an
octane rating below 87; as it may
cause engine damage and will lower
fuel economy.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are
available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
FlexFuel vehicles.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
(Continued)

Black plate (40,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
9-40 Driving and Operating
Caution (Continued)
That damage would not be
covered under the vehicle
warranty.
Some gasolines, mainly high octane
racing gasolines, can contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines and/or fuel additives with
MMT as they can reduce spark plug
life and affect emission control
system performance. The
malfunction indicator lamp may turn
on. If this occurs, see your dealer
for service.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle may not pass a smog-check
test. See
Malfunction Indicator
Lamp on page 5-17. If this occurs,
return to your authorized dealer for
diagnosis. If it is determined that the
condition is caused by the type of
fuel used, repairs may not be
covered by the vehicle warranty.
Fuels in Foreign
Countries
If planning to drive in countries
outside the U.S. or Canada, the
proper fuel might be hard to find.
Check regional auto club or fuel
retail brand websites for availability
in the country where driving. Never
use leaded gasoline, fuel containing
methanol, manganese, or any other
fuel not recommended. Costly repairs caused by use of improper
fuel would not be covered by the
vehicle warranty.
Fuel Additives
To keep fuel systems clean, TOP
TIER Detergent Gasoline is
recommended. See
Fuel on
page 9-39.
If TOP TIER Detergent Gasoline is
not available, one bottle of Fuel
System Treatment PLUS added to
the fuel tank at every engine oil
change can help. Fuel System
Treatment PLUS is the only
gasoline additive recommended by
General Motors. It is available at
your dealer.
Do not use additives with E85 or
FlexFuel.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or fuel
containing up to 85% ethanol (E85).

Black plate (41,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
Driving and Operating 9-41
All other vehicles should use only
the unleaded gasoline as described
inFuel on page 9-39.
The use of E85 or FlexFuel is
encouraged when the vehicle is
designed to use it. E85 or FlexFuel
is made from renewable sources.
To help locate fuel stations that
carry E85 or FlexFuel, the U.S.
Department of Energy has an
alternative fuels website. See
www.afdc.energy.gov/afdc/locator/
stations.
E85 or FlexFuel should meet ASTM
Specification D 5798 or CAN/
CGSB–3.512 in Canada. Do not use
the fuel if the ethanol content is
greater than 85%. Fuel mixtures that
do not meet ASTM or CGSB
specifications can affect driveability
and could cause the malfunction
indicator lamp to come on.
After refueling, the vehicle
calculates the composition of the
fuel. It is not recommended to
repeatedly switch between fuels.
If fuels are switched frequently, add as much fuel as possible and do not
add less than 11 L (3 gal) when
refueling. Drive at least 11 km (7 mi)
immediately after refueling to allow
the vehicle to adapt to the change in
ethanol concentration.
Because E85 or FlexFuel has less
energy per liter (gallon) than
gasoline, the vehicle will need to be
refilled more often. See
Filling the
Tank on page 9-41.
{Caution
Some additives are not
compatible with E85 or FlexFuel
and can harm the vehicle's fuel
system. Do not add anything to
E85 or FlexFuel. Damage caused
by additives would not be covered
by the vehicle warranty.
{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Filling the Tank
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
.To help avoid injuries to you
and others, read and follow
all the instructions on the fuel
pump island.
.Turn off the engine when
refueling.
(Continued)

Black plate (42,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
9-42 Driving and Operating
Warning (Continued)
.Keep sparks, flames, and
smoking materials away
from fuel.
.Do not leave the fuel pump
unattended.
.Do not reenter the vehicle
while pumping fuel.
.Keep children away from the
fuel pump and never let
children pump fuel.
.Fuel can spray out if the fuel
cap is opened too quickly.
This spray can happen if the
tank is nearly full, and is
more likely in hot weather.
Open the fuel cap slowly and
wait for any hiss noise to stop
then unscrew the cap all
the way.
The fuel cap is behind a hinged fuel
door on the driver side of the
vehicle.
If the vehicle has E85 fuel capability,
the fuel cap will be yellow and state
that E85 or gasoline can be used.
SeeE85 or FlexFuel on page 9-40.
To remove the fuel cap, turn it
slowly counterclockwise.
While refueling, hang the tethered
fuel cap from the hook on the
fuel door.
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:
.Vehicle performance issues,
including engine stalling and
damage to the fuel system.
.Fuel spills.
.Potential fuel fires.
Be careful not to spill fuel. Do not
top off or overfill the tank and wait a
few seconds after you have finished
pumping before removing the
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care on page 10-81.
When replacing the fuel cap, turn it
clockwise until it clicks. Make sure
the cap is fully installed. The
diagnostic system can determine if
the fuel cap has been left off or
improperly installed. This would

Black plate (44,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
9-44 Driving and Operating
Trailer Towing
General Towing
Information
Only use towing equipment that has
been designed for the vehicle.
Contact your dealer or trailering
dealer for assistance with preparing
the vehicle for towing a trailer. Read
the entire section before towing a
trailer.
For towing a disabled vehicle, see
Towing the Vehicle on page 10-79.
For towing the vehicle behind
another vehicle such as a motor
home, seeRecreational Vehicle
Towing on page 10-79.
Driving Characteristics
and Towing Tips
Driving with a Trailer
When towing a trailer:
.Become familiar with the state
and local laws that apply to
trailer towing.
.Do not tow a trailer during the
first 800 km (500 mi) to prevent
damage to the engine, axle,
or other parts.
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
.Vehicles can tow in D (Drive).
Shift the transmission to a lower
gear if the transmission shifts
too often under heavy loads and/
or hilly conditions.
.Turn off Park Assist when
towing.
{Warning
When towing a trailer, exhaust
gases may collect at the rear of
the vehicle and enter if the
liftgate, trunk/hatch, or rear-most
window is open.
(Continued)
Warning (Continued)
When towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
.Fully open the air outlets on
or under the instrument
panel.
.Also adjust the climate
control system to a setting
that brings in only outside air.
See“Climate Control
Systems” in the Index.
For more information about
Carbon Monoxide, see Engine
Exhaust on page 9-21.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is
longer and not as responsive as the
vehicle itself. Get acquainted with
the handling and braking of the rig
before setting out for the open road.

Black plate (45,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
Driving and Operating 9-45
Before starting, check all trailer hitch
parts and attachments, safety
chains, electrical connectors, lamps,
tires, and mirrors. If the trailer has
electric brakes, start the
combination moving and then apply
the trailer brake controller by hand
to be sure the brakes work.
During the trip, check occasionally
to be sure that the load is secure
and the lamps and any trailer
brakes still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy
braking and sudden turns.
Passing
More passing distance is needed
when towing a trailer. The
combination will not accelerate as
quickly and is longer so it is
necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up
Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
{Caution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance. If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades
Reduce speed and shift to a lower
gear
before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode on page 9-27.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off

Black plate (46,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - crc - 2/10/15
9-46 Driving and Operating
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine
off. If the overheat warning comes
on, seeEngine Overheating on
page 10-19.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface. If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet. Turn
the wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.