tow GMC SIERRA DENALI 2020 Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
6 Introduction
1. Tow/Haul Mode (On SomeModels). See Driver Mode
Control 0238.
Automatic Transfer Case
Control (If Equipped). See
Four-Wheel Drive 0227.
Driver Mode Control 0238 (If
Equipped).
2. Air Vents 0182.
3. Head-Up Display (HUD) 0152
(If Equipped).
4. Turn Signal Lever. See Turn
and Lane-Change Signals
0 170.
Windshield Wiper/Washer
0 119.
5. Instrument Cluster 0126.
6. Shift Lever. See Automatic
Transmission 0221.
Range Selection Mode. See
Manual Mode 0224.
7. Light Sensor. See Automatic
Headlamp System 0168.
8. Infotainment 0176. 9.
Climate Control Systems 0177
(If Equipped).
Dual Automatic Climate Control
System 0179 (If Equipped).
10. Heated and Ventilated Front
Seats 060 (If Equipped).
11.
ALane Keep Assist (LKA)
(1500 Series) 0278 (If
Equipped).
XPark Assist Switch (If
Equipped). See Assistance
Systems for Parking or Backing
0 257.
hAuto Stop Disable Switch
(If Equipped). See Stop/Start
System 0213.
5Power Release Tailgate
(If Equipped). See Tailgate
0 29.
|Hazard Warning Flashers
0 169.
gTraction Control/Electronic
Stability Control 0235.
ADC/AC Switch. See Power
Outlets 0121.
@Lane Departure Warning
(LDW) (2500/3500 Series)
0 276 (If Equipped).
5Hill Descent Control Switch
(If Equipped). See Hill Descent
Control (HDC) 0237.
jPower Assist Steps 034 (If
Equipped).
LExpress Window Down
Button (If Equipped). See
Power Windows 047.
Tow/Haul Mode 0227 (On
Some Models).
12. Power Outlet (Alternating Current) (If Equipped). See
Power Outlets 0121.
13. Power Outlets 0121.
14. USB Port. See the infotainment manual.
15. Wireless Charging 0122 (If
Equipped).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Introduction 7
16. Trailer Brake Control Panel (IfEquipped). See “Integrated
Trailer Brake Control System”
under Towing Equipment
0 296.
17. ENGINE START/STOP. See Ignition Positions (Keyless
Access) 0208 or
Ignition Positions (Key Access)
0 210.
18. Steering Wheel Controls (If Equipped). See the
infotainment manual.
Driver Information Center (DIC)
Controls. See Driver
Information Center (DIC) (Base
Level) 0147 or
Driver Information Center (DIC)
(Midlevel and Uplevel) 0148.
19. Horn 0119.
20. Hood Release. See Hood
0 330.
21. Steering Wheel Adjustment
0118 (Out of View). 22.
Cruise Control 0243.
Adaptive Cruise Control (1500
Series) 0245 (If Equipped).
Forward Collision Alert (FCA)
System 0268 (If Equipped).
Heated Steering Wheel 0119
(If Equipped).
23. Data Link Connector (DLC) (Out of View). See Malfunction
Indicator Lamp (Check Engine
Light) 0137.
24. Electric Parking Brake 0233.
25. Fog Lamps 0170 (If
Equipped).
Instrument Panel Illumination
Control 0172.
Exterior Cargo Lamps 0171.
Exterior Lamp Controls 0165.
Task Lighting 0171 (If
Equipped).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 9
Keys, Doors, and
Windows
Keys and Locks
Keys (Key Access) . . . . . . . . . . . . . . 9
Keys (Keyless Access) . . . . . . . . 12
Remote Keyless Entry (RKE)System . . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Key
Access) . . . . . . . . . . . . . . . . . . . . . . 13
Remote Keyless Entry (RKE) System Operation (Keyless
Access) . . . . . . . . . . . . . . . . . . . . . . 16
Remote Vehicle Start . . . . . . . . . . 25
Door Locks . . . . . . . . . . . . . . . . . . . . 26
Power Door Locks . . . . . . . . . . . . . 27
Delayed Locking . . . . . . . . . . . . . . . 27
Automatic Door Locks . . . . . . . . . 27
Lockout Protection . . . . . . . . . . . . . 28
Safety Locks . . . . . . . . . . . . . . . . . . . 28
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 29
Power Assist Steps . . . . . . . . . . . . 34
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 36
Vehicle Alarm System . . . . . . . . . 36 Steering Column Lock . . . . . . . . . 37
Immobilizer . . . . . . . . . . . . . . . . . . . . 37
Immobilizer Operation . . . . . . . . . 37
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 39
Manual Mirrors . . . . . . . . . . . . . . . . . 39
Trailer-Tow Mirrors . . . . . . . . . . . . . 40
Power Mirrors . . . . . . . . . . . . . . . . . . 41
Folding Mirrors . . . . . . . . . . . . . . . . . 42
Heated Mirrors . . . . . . . . . . . . . . . . . 43
Automatic Dimming Mirror . . . . . 43
Blind Spot Mirrors . . . . . . . . . . . . . . 43
Reverse Tilt Mirrors . . . . . . . . . . . . 44
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 44
Manual Rearview Mirror . . . . . . . . 44
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 44
Rear Camera Mirror . . . . . . . . . . . . 45
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 47
Manual Windows . . . . . . . . . . . . . . 47
Power Windows . . . . . . . . . . . . . . . 47
Rear Windows . . . . . . . . . . . . . . . . . 49
Sun Visors . . . . . . . . . . . . . . . . . . . . . 50
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 50
Keys and Locks
Keys (Key Access)
{Warning
Leaving children in a vehicle with
the ignition key is dangerous and
children or others could be
seriously injured or killed. They
could operate the power windows
or other controls or make the
vehicle move. The windows will
function with the keys in the
ignition, and children or others
could be caught in the path of a
closing window. Do not leave
children in a vehicle with the
ignition key.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
16 Keys, Doors, and Windows
2. Press and slide the batterydown toward the pocket of the
transmitter in the direction of
the key ring. Do not use a
metal object
3. Remove the battery.
4. Insert the new battery, positive side facing up. Replace with a
CR2032 or equivalent battery.
5. Push together the transmitter back cover top side first, and
then the bottom toward the
key ring.
Remote Keyless Entry
(RKE) System Operation
(Keyless Access)
The Keyless Access system allows
for vehicle entry when the
transmitter is within 1 m (3 ft). See
“Keyless Access Operation” later in
this section.
The RKE transmitter functions may
work up to 60 m (197 ft) away from
the vehicle.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 013.
The key that is part of the RKE
transmitter can be used for all locks.
Remove the key by pressing the
button on the side of the RKE
transmitter near the bottom and pull
the key out. Never pull the key out
without pressing the button.
See your dealer if a new transmitter
is needed.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 25
3. Lift the battery with a flatobject.
4. Remove the battery.
5. Insert the new battery, positive side toward the back cover.
Replace with a CR2032 or
equivalent battery.
6. Push together the transmitter.
7. Insert the key back into the RKE transmitter.
Remote Vehicle Start
If equipped with the remote start
feature, the climate control system
will come on when the vehicle is
started remotely, depending on the
outside temperature.
The rear defog and heated and
ventilated seats, if equipped, may
also come on. See Heated and
Ventilated Front Seats 060 and
Vehicle Personalization 0156.
If equipped, the automatic heated
steering wheel may also come on.
See Heated Steering Wheel 0119. Laws in some communities may
restrict the use of remote starters.
Check local regulations for any
requirements on remote starting of
vehicles.
Do not use remote start if the
vehicle is low on fuel. The vehicle
may run out of fuel.
The vehicle cannot be remote
started if:
.
The RKE transmitter is inside
the vehicle or if the key is in the
ignition.
. The hood is not closed.
. There is an emission control
system malfunction and the lamp
is on.
. The ignition is in any mode other
than off.
. The hazard warning flashers
are on.
. Two remote starts or a remote
start with an extension have
been used.
. The vehicle is not in P (Park). The engine will turn off during a
remote vehicle start if:
.
The coolant temperature gets
too high.
. The oil pressure gets low.
The RKE transmitter range may be
reduced while the vehicle is running.
Other conditions can affect the
performance of the transmitter. See
Remote Keyless Entry (RKE)
System 013.
Starting the Engine Using Remote
Start
1. Press and release
Q.
2. Immediately press and hold
/
until the turn signal lamps flash
or for at least four seconds.
When the vehicle starts, the
parking lamps will turn on. The
doors will be locked and the
climate control system may
come on.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 33
.To lower the tailgate step, press
the button at the center of the
step. Make sure it lowers to the
fully open position.
. To close the tailgate step, lift it
firmly. Make sure that both side
latches are engaged.Do not place a load on top of the
step when using it as a load stop.
Using the Assist Handle
The assist handle helps with
entering the pickup box. To use:
1. Lift up on the handle until it locks in the open position.
2. To return the assist handle, pull the release lever toward the
ball end of the handle and push
the handle back to the closed
position.
Applying Loads to Tailgates
Caution
Do not put ramp loads on the
inner tailgate alone. Damage to
the inner tailgate may occur.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 35
same side to complete the motion.
If the obstruction is not cleared, the
assist steps remain extended.
Slight movement of the steps while
extended is normal.
Kick Switch
1. Place the vehicle in P (Park)and unlock the doors.
2. Kick the switch to extend the power assist step to the tire.
A Driver Information Center
(DIC) message displays.
3. Kick the switch again to return to normal operation.
Center Stack Switch
The power assist steps can be
extended to the tire by pressing
j.
When extending the steps with
j,
the kick switch is disabled. The
vehicle must be in P (Park) or
N (Neutral).
To extend the steps:
. Press
jto extend both steps.
A DIC message displays.
. Press
jagain to extend to the
tire. A DIC message displays. .
Press
jagain to return to
normal operation.
Enable/Disable
To enable or disable the power
assist steps, press and hold
jfor
four seconds. A DIC message
displays.
Cleaning
Clean the power assist steps
regularly. For an automatic car
wash, extend the steps while in
N (Neutral) using the center stack
switch. The steps will stow when
shifting into D (Drive).

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Keys, Doors, and Windows 39
service. If the vehicle does start, the
first key may be faulty. See your
dealer. It is possible for the
immobilizer system to learn new or
replacement keys. Up to eight keys
can be programmed for the vehicle.
To program additional keys, see
Keys (Key Access)09or
Keys (Keyless Access) 012. Do not
leave the key or device that disarms
or deactivates the vehicle theft
system in the vehicle.
See your dealer to get a new key
blank cut exactly as the ignition key
that operates the system.Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you
cut too sharply into the right lane,
you could hit a vehicle on the
right. Check the inside mirror or
glance over your shoulder before
changing lanes.
Standard Mirrors
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from
the driver seat. Trailer-Tow Mirrors
The upper portion of both the driver
and passenger mirrors is flat.
The lower portion of both the driver
and passenger mirrors is convex.
A convex mirror
’s surface is curved
so more can be seen from the driver
seat. The lower portion is adjusted
manually.
Manual Mirrors
If equipped, adjust manual mirrors
by moving the mirror up and down
or left to right to see a little of the
side of the vehicle and to have a
clear view behind the vehicle.
Using hood-mounted air deflectors
and add-on convex mirror
attachments could decrease mirror
performance.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
40 Keys, Doors, and Windows
Trailer-Tow Mirrors
Extending Mirrors
Trailer tow mirrors can extend out
for better visibility when towing a
trailer.
Manual Extend :If equipped, grasp
the mirror housing firmly and pull
back in one motion, arching slightly
toward the rear of the vehicle.
To return the mirror to its original
position, reverse the motion.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
42 Keys, Doors, and Windows
Turn Signal Indicator
If equipped, the mirror has turn
signal indicator lights, which flash in
the direction of the turn or lane
change.
Task Lighting
If equipped, task lighting projects
light from the outside mirrors to the
sides of the vehicle. SeeTask
Lighting 0171.
Puddle Lamps
If equipped, puddle lamps project
light from the bottom of the mirror to
the area of ground below the driver
and passenger doors. See Entry
Lighting 0173 and
Exit Lighting 0173.
Memory Mirrors
The vehicle may have memory
mirrors. See Memory Seats 058.
Lane Change Alert (LCA)
The vehicle may have LCA. See
Lane Change Alert (LCA) 0274.Folding Mirrors
Manual Folding Mirrors
If equipped, push the mirror toward
the vehicle to fold. Push the mirror
outward to return to its original
position.
Manually fold the mirrors inward to
prevent damage when going
through an automatic car wash.
Power Folding Mirrors
If equipped with power folding
mirrors:
1. Press
gto fold the mirrors in
to the folded position.
2. Press
gagain to fold the
mirrors out to the driving
position.
Resetting the Power Folding
Mirrors
Reset the power folding mirrors if:
. The mirrors are accidentally
obstructed while folding.
. The mirrors are accidentally
manually folded/unfolded.
. The mirrors will not stay in the
unfolded position.
. The mirrors vibrate at normal
driving speeds.
Manually fold both mirrors if they
are out of sync. Fold and unfold the
mirrors three times using the mirror
controls to reset them to their
normal position. A popping noise
may be heard. This sound is normal
after a manual folding operation.