
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
Driving and Operating 291Trailer Brake Control Panel
1. Manual Trailer Brake Apply
Lever
2. Trailer Symbol
3. Trailer Gain Adjustment
Buttons
The trailer symbol on the control
panel will light amber when a trailer
with electric brakes is connected.
The ITBC control panel is on the
instrument panel to the right of the
steering column. See Instrument
Panel 0 6 . The control panel allows
adjustment to the amount of output,
referred to as Trailer Gain, available to the trailer brakes and allows
manual application of the trailer
brakes. Use the ITBC control panel
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
TRAILER GAIN: 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.
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
displays.
.
A trailer with electric brakes has
become disconnected, a CHECK
TRAILER WIRING message
displays on the DIC.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/16/18
292 Driving and Operating .
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 right to apply the
trailer ’ s electric brakes independent
of the vehicle ’ s brakes. Use this
lever to adjust Trailer Gain to
achieve 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.
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. { WarningTrailer 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.
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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
326 Vehicle Care 4. Press to confirm to reset.
5. If the vehicle is not equipped
with DIC buttons, depress the
thumbwheel or trip odometer
reset stem for several seconds
to reset the air filter life system.
Engine Air Cleaner/Filter If the vehicle has a diesel engine,
see “ Engine Air Cleaner/Filter ” in
the Duramax diesel supplement for
the correct inspection and
replacement procedures.
The engine air cleaner/filter is on
the driver side of the engine
compartment. See Engine
Compartment Overview 0 316 .
When to Inspect the Engine Air
Cleaner/Filter For intervals on changing and
inspecting the engine air filter, see
Maintenance Schedule 0 415 .
If equipped with the engine air filter
life system, see Engine Air Filter
Life System 0 325 . If driving in very dusty areas, follow
the engine air filter inspecting and
changing intervals. See
Maintenance Schedule 0 415 .
How to Inspect the Engine Air
Cleaner/Filter Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/
filter, make sure that the engine air
cleaner/filter housing and nearby
components are free of dirt and
debris. Remove the engine air
cleaner/filter. Lightly tap and shake
the engine air cleaner/filter (away
from the vehicle), to release loose
dust and dirt. Inspect the engine air
cleaner/filter for damage, and
replace if damaged. Do not clean
the engine air cleaner/filter or
components with water or
compressed air. To inspect or replace the engine air
cleaner/filter:
5.3L V8 Engine (L84) Shown, 2.7L
L4 Engine (L3B), 4.3L V6 Engine
(LV3), 5.3L V8 Engine (L82), and
6.2L V8 Engine (L87) Similar
1. Air Duct Clamp
2. Electrical Harness
Connector
3. Screws
1. Locate the air cleaner/filter
assembly. See Engine
Compartment Overview 0 316 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
336 Vehicle Care turned on after new pads and wear
sensors are installed, a message
will display. Follow the prompts to
reset the system.
The brake pad life system can also
be manually reset:
1. Display Brake Pad Life on the
DIC.
See Driver Information Center
(DIC) (Midlevel and Uplevel)
0 160 or Driver Information
Center (DIC) (Base Level)
0 159 .
2. Press the thumbwheel or the
trip odometer reset stem if the
vehicle does not have DIC
buttons. Select front or rear
pads as appropriate.
3. Select YES on the confirmation
message, or press the trip
odometer reset stem on a base
level DIC. Repeat for pads on
the other axle if they were also
replaced. How to Disable the Brake Pad
Life System The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear
sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in
wear indicators that make a
high-pitched warning sound when
the brake pads are worn can still
determine when the pads should be
replaced. See Brakes 0 335 .
To turn off the brake pad life system:
1. Display Brake Pad Life on the
DIC.
See Driver Information Center
(DIC) (Midlevel and Uplevel)
0 160 or Driver Information
Center (DIC) (Base Level)
0 159 .
2. Select DISABLE.
To turn the brake pad life system
back on, follow the above steps but
select ENABLE in Step 2. Brake Fluid The brake master cylinder reservoir
is filled with GM approved DOT 4
brake fluid as indicated on the
reservoir cap. See Engine
Compartment Overview 0 316 for
the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a
level surface, the brake fluid level
should be between the minimum
and maximum marks on the brake
fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
.
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
370 Vehicle Care
Tire Pressure Monitor
Operation This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure shown on the Tire and Loading
Information label. See Vehicle Load
Limits 0 209 .
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. If the vehicle has DIC
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, see Driver Information
Center (DIC) (Midlevel and Uplevel)
0 160 or Driver Information Center
(DIC) (Base Level) 0 159 .
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information label
shows the size of the original
equipment tires and the correct inflation pressure for the tires when
they are cold. See Vehicle Load
Limits 0 209 , for an example of the
Tire and Loading Information label
and its location. Also see Tire
Pressure 0 367 .
The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See Tire Inspection
0 375 , Tire Rotation 0 376 and Tires
0 358 .
CautionTire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
OnStar 447
OnStar OnStar Overview OnStar Overview . . . . . . . . . . . . . 447
OnStar Services Emergency . . . . . . . . . . . . . . . . . . . 448
Security . . . . . . . . . . . . . . . . . . . . . . 449
OnStar Additional Information OnStar Additional
Information . . . . . . . . . . . . . . . . . . 449
OnStar Overview
= Voice Command Button
Q Blue OnStar Button
> Red Emergency Button
This vehicle may be equipped with a
comprehensive, in-vehicle system
that can connect to an OnStar
Advisor for Emergency, Security,
Navigation, Connections, and
Diagnostics Services. OnStar
services may require a paid service
plan and data plan. OnStar requires
the vehicle battery and electrical
system, cellular service, and GPS
satellite signals to be available and
operating. OnStar acts as a link to
existing emergency service
providers. OnStar may collect
information about you and your
vehicle, including location
information. See OnStar User Terms, Privacy Statement, and
Software Terms for more details
including system limitations at
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
The OnStar system status light is
next to the OnStar buttons. If the
status light is:
.
Solid Green: System is ready.
.
Flashing Green: On a call.
.
Red: Indicates a problem.
.
Off: System is off. Press
Q twice to speak with an OnStar
Advisor.
Press
Q or call 1-888-4ONSTAR
(1-888-466-7827) to speak to an
Advisor.
Functionality of the Voice Command
button may vary by vehicle and
region.