2012 CHEVROLET EXPRESS wiring

Black plate (26,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
3-26 Seats and Restraints
To turn the front outboard passenger
airbag on again, insert the ignition
key into the switch, push in, and
move the switch to the on position.
The front outboard passenger
frontal airbag is now enabled, and
may inflate. SeeAirbag On-Off
Light on page 5-15 for more
information.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle
should be serviced. There are parts
of the airbag system in several
places around the vehicle. Your
dealer and the service manual have
information about servicing the
vehicle and the airbag system. To
purchase a service manual, see
Service Publications Ordering
Information on page 13-11.
{Warning
For up to 10 seconds after the
vehicle is turned off and the
battery is disconnected, an airbag
can still inflate during improper
service. You can be injured if you
are close to an airbag when it
inflates. Avoid yellow connectors.
They are probably part of the
airbag system. Be sure to follow
proper service procedures, and
make sure the person performing
work for you is qualified to do so.
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet
metal, may keep the airbag system
from working properly. The
operation of the airbag system can
also be affected by changing any
parts of the front seats, safety belts,
the airbag sensing and diagnostic module, steering wheel, instrument
panel, any of the airbag modules,
ceiling or pillar garnish trim, front
sensors, rollover sensor module,
or airbag wiring.
Your dealer and the service manual
have information about the location
of the airbag sensors, sensing and
diagnostic module, and airbag
wiring.
If the vehicle has rollover roof-rail
airbags, see
Different Size Tires
and Wheels on page 10-60 for
additional important information.
If you have to modify your vehicle
because you have a disability and
you have questions about whether
the modifications will affect the
vehicle's airbag system, or if you
have questions about whether the
airbag system will be affected if the
vehicle is modified for any other
reason, call Customer Assistance.
See Customer Assistance Offices
on page 13-3.

Black plate (14,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
5-14 Instruments and Controls
Readings in the low warning zone
may occur when a large number of
electrical accessories are operating
in the vehicle and the engine is left
at an idle for an extended period.
This condition is normal since the
charging system is not able to
provide full power at engine idle. As
engine speeds are increased, this
condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power.
The vehicle can be only driven for a
short time with the reading in either
warning zone. If it must be driven,
turn off all unnecessary
accessories.
Readings in either warning zone
indicate a possible problem in the
electrical system. Have the vehicle
serviced as soon as possible.Safety Belt Reminders
Safety Belt Reminder Light
There is a safety belt reminder light
on the instrument cluster.
When the vehicle is started, this
light flashes and a chime may come
on to remind the driver to fasten
their safety belt. Then the light stays
on solid until the belt is buckled.
This cycle may continue several
times if the driver remains or
becomes unbuckled while the
vehicle is moving.
If the driver safety belt is buckled,
neither the light nor the chime
comes on.
Airbag Readiness Light
This light shows if there is an
electrical problem with the airbag
system. The system check includes
the airbag sensor(s), passenger
sensing system (if equipped), the
pretensioners (if equipped), the
airbag modules, the wiring, and the
crash sensing and diagnostic
module. For more information on the
airbag system, seeAirbag System
on page 3-17.
The airbag readiness light comes on
for several seconds when the
vehicle is started. If the light does
not come on then, have it fixed
immediately.

Black plate (52,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
9-52 Driving and Operating
Weight-Distributing Hitches
and Weight Carrying Hitches
A weight distributing hitch may be
useful with some trailers. Use the
following guidelines to determine if a
weight distributing hitch should
be used.
1. Body to Ground Distance
2. Front of Vehicle
When using a weight-distributing
hitch, the hitch must be adjusted so
the distance (1) remains the same
both before and after coupling the
trailer to the tow vehicle.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Always leave just enough slack so
the rig can turn. Never allow safety
chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 680 kg (1,500 lb) needs to have
its own brake system that is
adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted and
maintained properly.
Trailer Wiring Harness
The optional heavy-duty trailer
wiring package includes a wiring
harness, with a seven-pin connector
at the rear of the vehicle and a
four-wire harness assembly under
the driver side of the instrumentpanel. The four-wire harness
assembly comes without a
connector.
If the vehicle does not have a trailer
hitch, the seven-wire harness
assembly with connector is taped
together and located in a frame
pocket at the driver side rear left
corner of the frame.
If the vehicle has a trailer hitch, the
seven-wire harness assembly with
connector is attached to a bracket
on the hitch platform. In both cases,
the seven-wire harness has a
connector and includes a 30-amp
feed wire.
The seven-wire harness connector
contains the following trailer circuits:
.Light Green: Back-up Lamps
(10A fuse)**
.White: Ground
.Dark Blue: Trailer Brake Signal
.Dark Green: Right Rear Stop
and Turn Signal*

Black plate (34,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-34 Vehicle Care
Exterior LampBulb
Number
Headlamps
Composite
High-Beam
Headlamp 9005LL
Composite
Low-Beam
Headlamp 9006LL
Sealed Beam
Headlamp H6054
For replacement bulbs not listed
here, contact your dealer.Electrical System
Electrical System
Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is
too heavy, the circuit breaker opens
and closes, protecting the circuit
until the current load returns to
normal or the problem is fixed. This
greatly reduces the chance of circuit
overload and fire caused by
electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating. If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be
borrowed. Choose some feature of
the vehicle that is not needed to use
and replace it as soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.

Black plate (35,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
Vehicle Care 10-35
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.
Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.Fuses and Circuit
Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of fires caused by electrical
problems.
Look at the silver-colored band
inside the fuse. If the band is broken
or melted, replace the fuse. Be sure
you replace a bad fuse with a new
one of the identical size and rating.
Engine Compartment
Fuse Block
The fuse block is located in the
engine compartment on the driver
side of the vehicle.
{Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the
covers on any electrical
component.

Black plate (36,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-36 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Mini Fuse Usage
3 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 Cluster 11 Trailer Wiring
12 Inside Rear Vision Camera Module
13 Spare

Black plate (38,1)Chevrolet Express Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
7707481) - 2015 - CRC - 4/30/14
10-38 Vehicle Care
Mini Fuse Usage65 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
71 Fuel Heater/Flex Fuel Sensor
72 Body Control Module 6
73 Lighter/Data Link Connection
75 V6 Fuel Injectors
76 Spare Mini Fuse Usage
77 Oxygen Sensor 2 (Pre)
78 Engine Control Module Powertrain
79 Even Ignition/ Injectors
J-Case Fuse Usage 1 ABS Motor
2 ABS Module
41 Spare
42 Trailer Wiring
43 Fan High
44 Starter Solenoid
45 Engine Control Module/Powertrain
46 Spare
47 Fan Lo
74 Front Blower Relay Usage
15 Run/Crank
37 Spare
38 Fuel Pump
39 Crank
40 Air Conditioning Compressor
48 Fan High
49 Powertrain
50 Spare
57 Fan Low
60 Fan Control