wiring CHEVROLET SILVERADO 3500 2019 Owners Manual

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Seats and Restraints 89
{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,
including improperly repairing or
replacing, any parts of the following:.
Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
. Front seats, including stitching,
seams or zippers
. Seat belts
. Steering wheel, instrument
panel, overhead console, ceiling
trim, or pillar garnish trim
. Inner door seals, including
speakers
Your dealer and the service manual
have information about the location
of the airbag modules and sensors,
sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle may have a
passenger sensing system for the
front outboard passenger position,
which includes sensors that are part
of the passenger ’s seat. The
passenger sensing system may not
operate properly if the original seat
trim is replaced with non-GM
covers, upholstery, or trim; or with GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad
or device, installed under or on top
of the seat fabric, could also
interfere with the operation of the
passenger sensing system. This
could either prevent proper
deployment of the passenger
airbag(s) or prevent the passenger
sensing system from properly
turning off the passenger airbag(s).
See
Passenger Sensing System
0 84.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires
and Wheels 0390 for additional
important information.
If a snow plow is added to the
vehicle, the airbags should still work
properly. The airbag systems were
designed to work properly under a
wide range of conditions, including
snow plowing with vehicles that
have the optional snow plow prep
package (RPO VYU). Do not
change or defeat the snow plow's
“tripping mechanism.” If you do, it

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Instruments and Controls 143
Seat Belt Reminders
Driver Seat Belt Reminder
Light
There is a driver seat 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 seat 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 seat belt is buckled,
neither the light nor the chime
comes on.
Passenger Seat Belt Reminder
Light
There may be a passenger seat belt
reminder light near the passenger
airbag status indicator. See
Passenger Sensing System084.
For vehicles equipped with the
passenger seat belt reminder light,
when the vehicle is started this light
flashes and a chime may come on
to remind passengers to fasten their
seat belt. Then the light stays on
solid until the belt is buckled. This
cycle continues several times if the
passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on. The front passenger seat belt
reminder light and chime may turn
on if an object is put on the seat
such as a briefcase, handbag,
grocery bag, laptop, or other
electronic device. To turn off the
reminder light and/or chime, remove
the object from the seat or buckle
the seat belt.
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, the airbag modules,
the wiring, and the crash sensing
and diagnostic module. For more
information on the airbag system,
see
Airbag System 076.

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
176 Lighting
change. This causes the turn
signals to automatically flash three
times. It will flash six times if Tow/
Haul Mode is active. Holding the
turn signal lever for more than
one second will cause the turn
signals to flash until the lever is
released.
The lever returns to its starting
position whenever it is released.
If after signaling a turn or a lane
change the arrows flash rapidly or
do not come on, a signal bulb could
be burned out. If equipped with LED
turn signals, see your dealer.
Replace any burned out bulbs. If a
bulb is not burned out, check the
fuse. SeeFuses and Circuit
Breakers 0362.
Turn Signal On Chime
If the turn signal is left on for more
than 1.2 km (0.75 mi), a chime
sounds at each flash of the turn
signal. The message TURN
SIGNAL ON will also appear in the
Driver Information Center (DIC). To turn the chime and message off,
move the turn signal lever to the off
position.
Fog Lamps
If equipped, the control is on the
center of the exterior lamp control,
to the left of the steering column.
The ignition must be on for the fog
lamps to come on.
#:
Press to turn the fog lamps on
or off. A light will come on in the
instrument cluster.
When the fog lamps are turned on,
the parking lamps automatically
turn on. When the headlamps are changed
to high beam, the fog lamps go off.
When the high-beam headlamps are
turned off, the fog lamps will come
on again.
Some localities have laws that
require the headlamps to be on with
the fog lamps.
Auxiliary
Roof-Mounted Lamp
If equipped, this button includes
wiring provisions for a dealer or a
qualified service center to install an
auxiliary roof lamp.
This button is on the overhead
console.

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Lighting 177
When the wiring is connected to an
auxiliary roof-mounted lamp,
pressing the bottom of the button
will activate the lamp and illuminate
an indicator light at the bottom of
this button. Pressing the top of the
button will turn off the roof-mounted
lamp and indicator.
The emergency roof lamp circuit is
fused at 30 amps, so the total
current draw of the attached lamps
should be less than this value. The
attachment points for the roof lamp
circuits are two blunt cut wires
above the overhead console: a dark
green with blue stripe switched
power wire and a black ground wire.
For information on roof-mounted
emergency lamp installation, see
www.gmupfitter.com or contact your
dealer.
If the vehicle has this button, the
vehicle may have the snow plow
prep package. SeeAdd-On
Electrical Equipment 0318.Exterior Cargo Lamps
The cargo lamp provides more light
in the cargo area or on the sides of
the vehicle, if needed. The lamps
inside the pickup box and/or on the
outside mirrors also turn on,
if equipped.
Press the switch to turn the cargo
lamp on or off. An indicator light will
turn on when the lamp is turned on,
if equipped. The shift lever must be
in P (Park), R (Reverse),
or N (Neutral) to operate the cargo
lamp. The lights on the outside mirrors turn on if the shift lever is in
P (Park), R (Reverse),
or N (Neutral).
Become familiar with and follow all
state and local laws that apply to
cargo lamp operation.

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Driving and Operating 309
Caution (Continued)
may exceed the
maximum amperage rating of
30 amps.
Trailer Wiring Harness
Basic Trailer Wiring
If the vehicle is not equipped with a
trailer connector on the rear bumper,
a 7-wire trailering harness is tied to
the vehicles frame. The harness
requires the installation of a trailer
connector, which is available
through your dealer.
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
The seven-wire harness contains
the following trailer circuits:Stop/Turn
Signal Left Yellow/Blue
Stop/Turn
Signal Right Green/Brown Tail/Parking
Lamps
Gray/Brown
Reverse Lamps White/Green
Battery Feed Red/Violet
Ground Black
Electric Trailer
Brake Blue
Heavy-Duty Trailer Wiring Harness
Package
If equipped, the trailer wiring
harness, with a 7-pin connector and
a 4-pin connector, is mounted on
the vehicle's rear bumper.
The trailer connectors contain the
following circuits.
1. Ground
2. Tail Lamps
3. Left Turn/Brake
4. Right Turn/Brake

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
310 Driving and Operating
1. Left Turn/Brake
2. Tail Lamps
3. Reverse Lamps
4. Battery Feed
5. Right Turn/Brake
6. Electric Brakes
7. Ground
If equipped with the fifth wheel/
gooseneck trailer package, the
harness connector is mounted on
the inside of the pickup bed behind
the rear wheel.Camper/Fifth-Wheel Trailer Wiring
Package
For vehicles without the fifth wheel/
gooseneck trailer package, the
seven-wire camper harness is under
the rear bumper, attached to the
frame near the rear crossmember.
A connector must be added to the
wiring harness that connects to the
camper.
The harness contains the following
camper/trailer circuits: Stop/Turn
Signal Left Yellow/Blue
Stop/Turn
Signal Right Green/Brown Tail/Parking
Lamps
Gray/Brown
Reverse Lamps White/Green
Battery Feed Red/Violet
Ground Black
Electric Trailer
Brake Blue
If equipped with the heavy-duty
trailering option, see “Heavy-Duty
Trailer Wiring Harness Package”
earlier in this section. When the
camper-wiring harness is ordered
without the heavy-duty trailering
package, a seven-wire harness with
a seven-pin connector is at the rear
of the vehicle and is tied to the
vehicle's frame.
Electric Brake Control Wiring
Provisions
If the vehicle is not equipped with
an integrated trailer brake controller,
a trailer brake controller needs to be
installed on the vehicle if the trailer
has electric brakes. The brake
controller should be installed by

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Driving and Operating 311
your dealer or a qualified service
center. If equipped, wiring
provisions for an aftermarket electric
trailer brake controller are included
with the vehicle as part of the trailer
wiring package. The harness
contains the following circuits:Electric Trailer
Brakes Blue
Battery Feed Red/Black or
Red/Blue
Brake Apply
Signal White/Blue
Ground Black
Refer to the aftermarket electric
trailer brake controller owner's
manual to determine wire color
coding of the electric trailer brake
controller. The wire colors on the
brake controller may be different
from the vehicle. The fuse for the
electric trailer brake circuit is in the
engine compartment fuse block, but
the wires may not be connected.
They should be connected by your
dealer or a qualified service center.Trailer Lamps
Always check all trailer lamps are
working at the beginning of each
trip, and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals should will illuminate to
indicate the vehicle is turning,
changing lanes, or stopping. When
towing a trailer, the arrows on the
instrument cluster will illuminate
even if the trailer is not properly
connected or the bulbs are
burned out.
Tow/Haul Mode
For instructions on how to enter
Tow/Haul mode, see Tow/Haul
Mode 0261.
Tow/Haul assists when pulling a
heavy trailer or a large or
heavy load.
Tow/Haul Mode is designed to be
most effective when the vehicle and
trailer combined weight is at least
75% of the vehicle's Gross Combined Weight Rating (GCWR).
See
“Weight of the Trailer” under
Trailer Towing 0298.
Tow/Haul Mode is most useful when
towing a heavy trailer or carrying a
large or heavy load:
. through rolling terrain.
. in stop-and-go traffic.
. in busy parking lots.
Operating the vehicle in Tow/Haul
Mode when lightly loaded or not
towing will not cause damage;
however, it is not recommended and
may result in unpleasant engine and
transmission driving characteristics
and reduced fuel economy.Integrated Trailer Brake
Control System
TThe vehicle may have an
Integrated Trailer Brake Control
(ITBC) system for use with electric
trailer brakes or most electric over
hydraulic trailer brake system

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Driving and Operating 313
and the DIC trailer brake display
page to adjust and display power
output to the trailer brakes.
Trailer Brake DIC Display Page
The ITBC display page indicates
.Trailer Gain setting
. Output to the trailer brakes
. Trailer connection
. System operational status.
To display
. Scroll through the DIC menu
pages
. Press a Trailer Gain (+) or (−)
button
. Activate the Manual Trailer
Brake Apply Lever
Press a Trailer Gain button to recall
the current Trailer Gain setting.
Each press and release of the gain
buttons will then change the Trailer
Gain setting. TRAILER GAIN:
Press the Trailer Gain (+) or (−) to
adjust. Press and hold to
continuously adjust the Trailer Gain.
To turn the output to the trailer off,
adjust the Trailer Gain setting to 0.0.
This setting can be adjusted from
0.0 to 10.0 with a trailer connected
or disconnected.
TRAILER OUTPUT: This displays
anytime a trailer with electric brakes
is connected. Output to the trailer
brakes is based on the amount of
vehicle braking present and relative
to the Trailer Gain setting. Output is
displayed from 0 to 100% for each
gain setting.
The Trailer Output will indicate
“- - -
- - -” on the Trailer Brake Display
Page whenever the following occur:
. No trailer is connected.
. A trailer without electric brakes
is connected, no DIC message
will display .
A trailer with electric brakes has
become disconnected, a CHECK
TRAILER WIRING message
displays on the DIC
. There is a fault present in the
wiring to the trailer brakes, a
CHECK TRAILER WIRING
message displays on the DIC
. The ITBC system is not working
due to a fault, a SERVICE
TRAILER BRAKE SYSTEM
message displays in the DIC
Manual Trailer Brake Apply Lever
Slide this lever left to apply the
trailer ’s electric brakes independent
of the vehicle’s brakes. Use this
lever to adjust Trailer Gain to
achieve the proper power output to
the trailer brakes. The trailer's and
the vehicle's brake lamps will come
on when either vehicle brakes or
manual trailer brakes are applied
and properly connected.

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
314 Driving and Operating
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a
specific trailering condition and it
must be readjusted anytime vehicle
loading, trailer loading, or road
surface conditions change.
{Warning
Trailer brakes that are
over-gained or under-gained may
not stop the vehicle and the trailer
as intended and can result in a
crash. Always follow the
instructions to set the Trailer Gain
for the proper trailer stopping
performance.
To adjust Trailer Gain for each
towing condition: 1. Drive the vehicle with the trailer attached on a level road
surface representative of the
towing condition and free of
traffic at about 32 - 40 km/h
(20 - 25 mph) and fully apply
the Manual Trailer Brake Apply
Lever. Note
Adjusting Trailer Gain at speeds
lower than 32 to 40 km/h (20 to
25 mph) may result in an incorrect
gain setting.
2. Adjust the Trailer Gain, using the Trailer Gain (+) or (−)
adjustment Buttons, to just
below the point of trailer wheel
lock-up, indicated by trailer
wheel squeal or tire smoke
when a trailer wheel locks.
Note
Trailer wheel lock-up may not occur
if towing a heavily loaded trailer.
Adjust the Trailer Gain to the
highest allowable setting for the
towing condition.
3. Readjust Trailer Gain anytime vehicle loading, trailer loading,
or road surface conditions
change or if trailer wheel
lock-up is noticed at any time
while towing. Other ITBC-Related DIC Messages
TRAILER CONNECTED: This
message will briefly display when a
trailer with electric brakes is first
connected to the vehicle. This
message will automatically turn off
in about 10 seconds. This message
can be acknowledged before it
automatically turns off.
CHECK TRAILER WIRING: This
message will display if:
.
The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected the vehicle.
If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about 30 seconds. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This

Chevrolet Silverado LD 1500 and Silverado 2500/3500 Owner Manual (GMNA-
Localizing-U.S./Canada-12162993) - 2019 - crc - 4/4/18
Driving and Operating 315
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
. There is an electrical fault in the
wiring to the trailer brakes. This
message will continue as long
as there is an electrical fault in
the trailer wiring. This message
will also turn off if it is
acknowledged.
To determine whether the electrical
fault is on the vehicle side or trailer
side of the trailer wiring harness
connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition off.
3. Wait 10 seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message reappears,
the electrical fault is on the
vehicle side. If the CHECK TRAILER WIRING
message only reappears when
connecting the trailer wiring harness
to the vehicle, the electrical fault is
on the trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message
continues over multiple ignition
cycles, have the vehicle serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty. Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.
Trailer Sway
Control (TSC)
Vehicles with StabiliTrak have a
Trailer Sway Control (TSC) feature.
Trailer sway is unintended
side-to-side motion of a trailer while
towing. If the vehicle is towing a
trailer and the TSC detects that
sway is increasing, the vehicle
brakes are selectively applied at
each wheel, to help reduce
excessive trailer sway. If equipped
with the Integrated Trailer Brake
Control (ITBC) system, and the
trailer has an electric brake system,
StabiliTrak may also apply the trailer
brakes.