Page 295 of 472

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
294 Driving and Operating 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/ESC may also apply the
trailer brakes.
If TSC is enabled, the Traction
Control System (TCS)/StabiliTrak/
ESC warning light will flash on the
instrument cluster. Reduce vehicle
speed by gradually removing your
foot from the accelerator. If trailer
sway continues, StabiliTrak/ESC
can reduce engine torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned
off. See Traction Control/Electronic
Stability Control 0 243 .
{ WarningTrailer sway can result in a crash
and in serious injury or death,
even if the vehicle is equipped
with TSC.
If the trailer begins to sway,
reduce vehicle speed by
gradually removing your foot from
the accelerator. Then pull over to
check the trailer and vehicle to
help correct possible causes,
including an improperly or
overloaded trailer, unrestrained
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. See Towing
Equipment 0 285 for trailer ratings
and hitch setup
recommendations. Aftermarket 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 DIC. The effects of
these aftermarket devices may have
on vehicle handling or trailer brake
performance is not known.
{ Warning
Use of aftermarket electronic
trailer sway control devices could
result in reduced trailer brake
performance, loss of trailer
brakes, or other malfunctions, and
(Continued)
Page 307 of 472

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
306 Driving and Operating If Tow/Haul Mode is off and this
setting is on for a Trailer Profile,
each time the ignition is turned on a
reminder will appear to turn on Tow/
Haul Mode when the Trailer Profile
is active.
If Tow/Haul Mode is on and this
setting is on for a Trailer Profile, the
reminder will not appear when the
Trailer Profile is active.
Conversions and
Add-Ons Add-On Electrical
Equipment
{ WarningThe Data Link Connector
(DLC) is used for vehicle service
and Emission Inspection/
Maintenance testing. See
Malfunction Indicator Lamp
(Check Engine Light) 0 149 .
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. CautionSome 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 0 96 and Adding Equipment
to the Airbag-Equipped Vehicle
0 97 .
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.
Page 350 of 472

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
Vehicle Care 349To 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.
License Plate Lamp To replace the bulb:
1. Reach behind the rear bumper
and locate the bulb. 2. Turn the bulb socket
counterclockwise and pull the
bulb straight out of the socket.
3. Replace the bulb and reverse
Step 2 to reinstall.Electrical System 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.
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.
Page 351 of 472

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
350 Vehicle Care 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. { DangerFuses 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 passenger side of the vehicle.
Lift the cover to access the fuse
block.