Black plate (57,1)Chevrolet Express Owner Manual - 2012
Driving and Operating 9-57
The four-wire harness (without
connector) contains the following
circuits:
.Black: Ground
.Red/White: Battery Feed
.Dark Blue: Trailer Brake Signal
.Light Blue: CHMSL/Stoplamp
Supply Voltage
* If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for both left/stop trailer
turn and right/stop trailer turn
signals. However, the cutaway
lighting connector will have a
10 amp fuse for each signal.
** If the vehicle is a cutaway with
trailer provisions, a 15 amp fuse will
be shared for trailer park lamps and
cutaway rear lighting connector park
lamps. Also, a 10 amp fuse will be
shared for trailer back-up lamps and
cutaway rear lighting connector
back-up lamps.
Tow/Haul Mode
This button is on the instrument
panel, to the right of the steering
wheel.
Pressing this button turns on and off
the Tow/Haul Mode.
This indicator light on the instrument
panel cluster comes on when the
Tow/Haul Mode is on.
Tow/Haul is a feature that assists
when pulling a heavy trailer or a
large or heavy load. See Tow/Haul
Mode on page 9‑32 for more
information. Tow/Haul is designed to be most
effective when the vehicle and
trailer combined weight is at least
75 percent of the vehicle Gross
Combined Weight Rating (GCWR).
See
“Weight of the Trailer” inTrailer
Towing on page 9‑50. Tow/Haul is
most useful under the following
driving conditions:
.When pulling a heavy trailer or a
large or heavy load through
rolling terrain.
.When pulling a heavy trailer or a
large or heavy load in stop and
go traffic.
.When pulling a heavy trailer or a
large or heavy load in busy
parking lots where improved low
speed control of the vehicle is
desired.
Black plate (58,1)Chevrolet Express Owner Manual - 2012
9-58 Driving and Operating
Operating the vehicle in Tow/Haul
when lightly loaded or with no trailer
at all will not cause damage.
However, there is no benefit to the
selection of Tow/Haul when the
vehicle is unloaded. Such a
selection when unloaded may
result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy. Tow/
Haul is recommended only when
pulling a heavy trailer or a large or
heavy load.Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice:Do not add anything
electrical to the vehicle unless
you check with your dealer first.
Some electrical equipment can
damage the vehicle and the
damage would not be covered by
the vehicle's warranty. Some
add-on electrical equipment can
keep other components from
working as they should. Add-on equipment can drain the
vehicle's 12‐volt battery, even if
the vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle on page 3‑35
andAdding
Equipment to the Airbag-Equipped
Vehicle on page 3‑35.
Black plate (1,1)Chevrolet Express Owner Manual - 2012
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 . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . . 10-7
Engine Oil Life System . . . . . 10-10
Automatic Transmission Fluid (4-Speed Transmission) . . . 10-11
Automatic Transmission Fluid (6-Speed
Transmission) . . . . . . . . . . . . . 10-13
Engine Air Cleaner/Filter . . . . 10-16
Cooling System . . . . . . . . . . . . 10-18
Engine Coolant . . . . . . . . . . . . . 10-18
Engine Overheating . . . . . . . . 10-22 Engine Fan . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-28
All-Wheel Drive . . . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-30
Rear Axle . . . . . . . . . . . . . . . . . . 10-31
Noise Control System . . . . . . 10-31
Starter Switch Check . . . . . . . 10-33
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-33
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-33
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-34
Wiper Blade Replacement . . . . . . . . . . . . . . 10-34
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-35
Halogen Bulbs . . . . . . . . . . . . . . 10-35
Headlamps . . . . . . . . . . . . . . . . . 10-35
Front Turn Signal,Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . 10-37
Taillamps . . . . . . . . . . . . . . . . . . . 10-38 Center High-Mounted
Stoplamp (CHMSL) . . . . . . . 10-39
License Plate Lamp . . . . . . . . 10-40
Replacement Bulbs . . . . . . . . . 10-40
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-41
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-42
Floor Console Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-46
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-49
Tire Sidewall Labeling . . . . . . 10-50
Tire Designations . . . . . . . . . . . 10-52
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . 10-54
Tire Pressure . . . . . . . . . . . . . . . 10-56
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-58
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-59
Tire Inspection . . . . . . . . . . . . . . 10-62
Tire Rotation . . . . . . . . . . . . . . . 10-62
Dual Tire Rotation . . . . . . . . . . 10-64
Black plate (7,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-7
A.Battery on page 10‑28.
B. Radiator Pressure Cap. See Cooling System on page 10‑18.
C. Coolant Recovery Tank. See Cooling System on page 10‑18.
D. Automatic Transmission Fluid Dipstick. See “Checking the
Fluid Level” underAutomatic
Transmission Fluid (4-Speed
Transmission) on page 10‑11 or
Automatic Transmission Fluid
(6-Speed Transmission) on
page 10‑13.
E. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil on page 10‑7.
F. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10‑7.
G. Engine Air Cleaner/Filter on
page 10‑16.
H. Power Steering Fluid Reservoir. See Power Steering Fluid on
page 10‑24. I. Brake Master Cylinder
Reservoir. See Brake Fluid on
page 10‑27.
J. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10‑25.
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 10‑10.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Black plate (28,1)Chevrolet Express Owner Manual - 2012
10-28 Vehicle Care
After work is done on the brake
hydraulic system, make sure the
level is above the MIN but not over
the MAX mark.
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11‑12.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.
{WARNING
With the wrong kind of fluid in the
brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid.Notice
.Using the wrong fluid
can badly damage brake
hydraulic system parts. For
example, just a few drops of
mineral-based oil, such as
engine oil, in the brake
hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Be careful not to
spill brake fluid on the
vehicle. If you do, wash it
off immediately.
Battery
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview on
page 10‑6
for battery location.
{WARNING
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.
Black plate (29,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-29
Vehicle Storage
{WARNING
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. SeeJump Starting on
page 10‑86 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
All-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule
to determine how often to check the
lubricant. See Maintenance
Schedule on page 11‑3.
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.
A. Drain Plug
B. Fill Plug
If the level is below the bottom of
the fill plug hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug hole. Use care
not to overtighten the plug.
What to Use
Refer to Recommended Fluids and
Lubricants on page 11‑12 to
determine what kind of lubricant
to use.
Black plate (43,1)Chevrolet Express Owner Manual - 2012
Vehicle Care 10-43
Mini Fuse Usage3 Right Stop/Turn
Trailer
4 Spare
5 Spare
6 Fuel System
Control Module
Ignition
7 Body Control
Module 5
8 Body Control
Module 7
9 Body Control
Module 4
10 Instrument Panel
Cluster Mini Fuse Usage
11 Trailer Wiring
12 Spare
13 Spare
14 Windshield Washer
16 Horn
17 Transmission
18 Air Conditioning
Compressor
19 Engine Control
Module Battery
20 Spare
21 Left Stop/Turn
Trailer Mini Fuse Usage
22 Spare
23 Spare
24 Fuel Pump
25 Auxiliary Power
Outlet
26 Body Control
Module 3
27 Special Equipment
Option
28 Airbag
29 Steering Wheel
Sensor
30 Engine Control
Module Ignition/
Glow Plug Module
Black plate (44,1)Chevrolet Express Owner Manual - 2012
10-44 Vehicle Care
Mini Fuse Usage31 Transmission
Control Module
Ignition
32 Transmission
Control Module
Battery
33 Spare
34 Spare
35 Fuel Operated
Heater Module
36 Fuel System
Control Module
Battery
51 Left High‐Beam
Headlamp
52 Right High‐Beam
Headlamp Mini Fuse Usage
53 Left Low‐Beam
Headlamp
54 Right Low‐Beam
Headlamp
55 Wiper
56 Canister Vent
Solenoid
58 Body Control
Module 2
59 Body Control
Module 1
61 Spare
62 Oxygen Sensor 2
(Post), EV Fan
(Diesel)
63 Spare Mini Fuse Usage
64 Mass Air Flow/
Canister Vent
65 Odd Ignition/
Injectors
66 Daytime Running
Lamps 2
(LOLVL‐V22)
(If Equipped)
67 Daytime Running
Lamps 1
(UPLVL+V22)
(If Equipped)
68 Auxiliary Stop
Lamps
69 Trailer Stop Lamps
70 Spare