2018 CHEVROLET SILVERADO wiring

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
Driving and Operating 327
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
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 if 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, there is a problem with the
ITBC system. 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
being towed. 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 the vehicle
is equipped with the Integrated
Trailer Brake Control (ITBC) system,
and the trailer has the electric
actuated brake system, StabiliTrak
may also apply the trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak
warning light will flash on the

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
328 Driving and Operating
instrument cluster. Vehicle speed
must be reduced. If trailer sway
continues, StabiliTrak can reduce
engine torque to help slow the
vehicle. SeeTraction Control/
Electronic Stability Control 0276.
{Warning
Even if the vehicle is equipped
with TSC, trailer sway could result
in loss of control and the vehicle
could crash. If excessive trailer
sway is detected, slow down to a
safe speed. Check the trailer and
vehicle to help correct possible
causes. These could include an
improperly or overloaded trailer,
unrestrained cargo, improper
trailer hitch configuration,
excessive vehicle-trailer speed,
or improperly inflated or incorrect
vehicle or trailer tires. See Towing
Equipment 0318 for trailer
ratings and hitch setup
recommendations. Adding non-dealer accessories can
affect the vehicle performance. See
Accessories and Modifications
0
336.
Electronic Trailer Sway Control
Devices
Some trailers may come equipped
with an electronic device designed
to reduce or control trailer sway.
Aftermarket equipment
manufacturers also offer similar
devices that connect to the wiring
between the trailer and the vehicle.
These devices may interfere with
the vehicle’ s trailer brake or other
systems, including integrated
anti-sway systems, if equipped.
Messages related to trailer
connections or trailer brakes could
appear on the Driver Information
Center (DIC). The effect that these
devices may have on vehicle
handling or trailer brake
performance is unknown.
{Warning
Use of electronic trailer sway
control devices could result in
reduced trailer brake
performance, loss of trailer
brakes, or other malfunctions, and
could cause a crash. You or
others could be injured or killed.
Before using one of these
devices:
. Ask the device or trailer
manufacturer if the device
has been thoroughly tested
for compatibility with the
make, model, and year of
the vehicle as well as
optional equipment installed
on the vehicle.
. Before driving on the open
roads, check that the trailer
brakes are working properly.
Drive the vehicle with the
trailer attached on a level
road surface that is free of
traffic at about 32-40 km/h
(Continued)

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
Driving and Operating 329
Warning (Continued)
(20-25 mph) and fully apply
the manual trailer brake
apply lever. Also check that
the trailer brake lamps and
other lamps are functioning
correctly.
. If the trailer brakes are not
operating properly at any
time, or if a DIC message
indicates problems with the
trailer connections or trailer
brakes, carefully pull the
vehicle over to the side of
the road when traffic
conditions allow.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service
and Emission Inspection/
Maintenance testing. See
Malfunction Indicator Lamp
(Check Engine Light) 0147.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
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 090 and Adding Equipment
to the Airbag-Equipped Vehicle
0 90.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
Driving and Operating 333
go to a weigh station and weigh the
vehicle. Your dealer can also help
with this.
The total vehicle reserve capacity
for the vehicle is in the lower right
corner of the Certification/Tire label
as shown previously.
See your dealer for additional
advice and information about using
a snow plow on the vehicle. Also,
seeVehicle Load Limits 0239.
Emergency Roof Lamp
Provisions
Vehicles with the RPO VYU snow
plow prep package also have an
emergency roof lamp provision
package, RPO TRW. Wiring for the
emergency roof lamp is provided
above the overhead console. See
Auxiliary Roof-Mounted Lamp 0176
for switch location.
Pickup Conversion to
Chassis Cab
We are aware that some vehicle
owners might consider having the
pickup box removed and a
commercial or recreational body
installed. Owners should be aware
that, as manufactured, there are
differences between a chassis cab
and a pickup with the box removed
which could affect vehicle safety.
The components necessary to adapt
a pickup to permit its safe use with
a specialized body should be
installed by the body builder.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
334 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . . . . . 335
California Proposition65 Warning . . . . . . . . . . . . . . . . . 336
California Perchlorate Materials Requirements . . . . . 336
Accessories and Modifications . . . . . . . . . . . . . . . . 336
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 337
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 337
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 338
Engine Oil . . . . . . . . . . . . . . . . . . . . 343
Engine Oil Life System . . . . . . . 346
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 347
Automatic Transmission Fluid (8-Speed Transmission) . . . . . 350
Manual Transmission Fluid . . . 350
Hydraulic Clutch . . . . . . . . . . . . . . 351
Engine Air Cleaner/Filter . . . . . . 351
Cooling System . . . . . . . . . . . . . . 352
Engine Overheating . . . . . . . . . . 356 Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . 358
Engine Fan . . . . . . . . . . . . . . . . . . . 358
Power Steering Fluid (1500 Series) . . . . . . . . . . . . . . . . . . . . . . 359
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 359
Washer Fluid . . . . . . . . . . . . . . . . . 359
Brakes . . . . . . . . . . . . . . . . . . . . . . . 360
Brake Fluid . . . . . . . . . . . . . . . . . . . 361
Battery - North America . . . . . . 362
Four-Wheel Drive . . . . . . . . . . . . . 363
Front Axle . . . . . . . . . . . . . . . . . . . . 364
Rear Axle . . . . . . . . . . . . . . . . . . . . 365
Noise Control System . . . . . . . . 366
Starter Switch Check . . . . . . . . . 367
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 368
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 368
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 368
Wiper Blade Replacement . . . . 369
Windshield Replacement . . . . . 369
Gas Strut(s) . . . . . . . . . . . . . . . . . . 370
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 371
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 371
Halogen Bulbs . . . . . . . . . . . . . . . . 371
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 371
LED Lighting . . . . . . . . . . . . . . . . . 371
Headlamps, Front Turn Signal,
Sidemarker, and Parking
Lamps . . . . . . . . . . . . . . . . . . . . . . 372
Fog Lamps . . . . . . . . . . . . . . . . . . . 373
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . . . 373
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 373
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 375
Electrical System
High Voltage Devices andWiring . . . . . . . . . . . . . . . . . . . . . . . 375
Electrical System Overload . . . 375
Fuses and Circuit Breakers . . . 376
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 376
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 380
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 381

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
Vehicle Care 375
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp
1. Cargo Lamp Bulbs
2. Center High-MountedStoplamp (CHMSL) Bulb
To replace one of these bulbs:
1. Remove the two screws and lift off the lamp assembly.
2. Turn the bulb socket counterclockwise and pull it
straight out.
3. Pull the bulb straight out from the socket.
Electrical System
High Voltage Devices and
Wiring
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
Electrical System
Overload
The vehicle has fuses to protect
against an electrical system
overload. Fuses also 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, there
are some spare fuses and a fuse
puller in the left instrument panel
fuse block. The same amperage
fuse can also be borrowed. Choose
some feature of the vehicle that is
not needed to use and replace it as
soon as possible.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
376 Vehicle Care
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.
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 damage caused by
electrical problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit
breakers. Use of an oversized
fuse or circuit breaker can result
in a vehicle fire. You and others
could be seriously injured or
killed.
To check a fuse, look at the
silver-colored band inside the fuse.
If the band is broken or melted,
replace the fuse. Be sure to replace
a bad fuse with a new one of the
identical size and rating. Fuses of the same amperage can
be temporarily borrowed from
another fuse location, if a fuse goes
out. Replace the fuse as soon as
possible.
Engine Compartment
Fuse Block
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
The engine compartment fuse block
is in the engine compartment, on
the driver side of the vehicle.

Chevrolet Silverado Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
11349200) - 2018 - CRC - 2/27/18
492 Index
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 371
Hazard Warning Flashers . . . . . . . 175
Head Restraints . . . . . . . . . . . . . . . . . 58
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 371
Automatic . . . . . . . . . . . . . . . . . . . . . 174
Bulb Replacement . . . . . . . . . . . . 371
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . 174
Flash-to-Pass . . . . . . . . . . . . . . . . . 174
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . . . 372
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . 371
High-Beam On Light . . . . . . . . . . 154
High/Low Beam Changer . . . . . 173
Lamps On Reminder . . . . . . . . . 154
Heated Steering Wheel . . . . . . . . . . . . . . . 130
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Heated Mirrors . . . . . . . . . . . . . . . . . . . 50
Heater
Engine Coolant . . . . . . . . . . . . . . . 252
Heating . . . . . . . . . . . . . . .216, 218, 220 High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 375
High-Beam On Light . . . . . . . . . . . . 154
High-Speed Operation . . . . . . . . . . 394
Hill and Mountain Roads . . . . . . . . 236
Hill Descent Control (HDC) . . . . . 277
Hill Descent Control Light . . . . . . . 151
Hill Start Assist (HSA) . . . . . . . . . . 275
Home Page . . . . . . . . . . . . . . . . . . . . . 184
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 70
HVAC . . . . . . . . . . . . . . . . .216, 218, 220
Hydraulic Clutch . . . . . . . . . . . . . . . . 351
I
Idle System Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Ignition Positions . . . . . . . . . . . . . . . 248
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 368
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 46
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . 152
Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . 94
Infotainment . . . . . . . . . . . . . . . . . . . . 181 Infotainment System . . . . . . . . . . . . 474
Instrument Cluster . . . . . . . . . . . . . . 137
Instrument Panel
Storage Area . . . . . . . . . . . . . . . . . 124
Interior Rearview Mirrors . . . . . . . . . 51
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . 195
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . 421
K
Keyless Entry
Remote (RKE) System . . . . . . . . . 37
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
L
Labeling, Tire Sidewall . . . . . . . . . . 386
Lamps
Auxiliary RoofMounted Lamp . . . . . . . . . . . . . . 176
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 177
Daytime Running (DRL) . . . . . . 174
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 178
Exterior Controls . . . . . . . . . . . . . . 171
Exterior Lamps Off Reminder . . . . . . . . . . . . . . . . . . . 173