2020 GMC SIERRA sunroof

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
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) . . . . . . . . . . . . . . . . . . . . . . 15
Remote Vehicle Start . . . . . . . . . . 24
Door Locks . . . . . . . . . . . . . . . . . . . . 25
Power Door Locks . . . . . . . . . . . . . 26
Delayed Locking . . . . . . . . . . . . . . . 26
Automatic Door Locks . . . . . . . . . 26
Lockout Protection . . . . . . . . . . . . . 27
Safety Locks . . . . . . . . . . . . . . . . . . . 27
Doors
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . 28
Power Assist Steps . . . . . . . . . . . . 36
Vehicle Security
Vehicle Security . . . . . . . . . . . . . . . . 37
Vehicle Alarm System . . . . . . . . . 37 Steering Column Lock . . . . . . . . . 38
Immobilizer . . . . . . . . . . . . . . . . . . . . 39
Immobilizer Operation . . . . . . . . . 39
Exterior Mirrors
Convex Mirrors . . . . . . . . . . . . . . . . 40
Manual Mirrors . . . . . . . . . . . . . . . . . 41
Trailer-Tow Mirrors . . . . . . . . . . . . . 41
Power Mirrors . . . . . . . . . . . . . . . . . . 43
Folding Mirrors . . . . . . . . . . . . . . . . . 43
Heated Mirrors . . . . . . . . . . . . . . . . . 44
Automatic Dimming Mirror . . . . . 44
Blind Spot Mirrors . . . . . . . . . . . . . . 44
Reverse Tilt Mirrors . . . . . . . . . . . . 45
Interior Mirrors
Interior Rearview Mirrors . . . . . . . 46
Manual Rearview Mirror . . . . . . . . 46
Automatic Dimming Rearview
Mirror . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rear Camera Mirror . . . . . . . . . . . . 46
Windows
Windows . . . . . . . . . . . . . . . . . . . . . . . 48
Manual Windows . . . . . . . . . . . . . . 49
Power Windows . . . . . . . . . . . . . . . 49
Rear Windows . . . . . . . . . . . . . . . . . 51
Sun Visors . . . . . . . . . . . . . . . . . . . . . 51
Roof
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . 51
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 - 4/4/19
Keys, Doors, and Windows 49
The vehicle aerodynamics are
designed to improve fuel economy
performance. This may result in a
pulsing sound when either rear
window is down and the front
windows are up. To reduce the
sound, open either a front window
or the sunroof, if equipped.
Manual Windows
If equipped, turn the hand crank on
each door to manually raise or lower
the manual windows.
Power Windows
{Warning
Children could be seriously
injured or killed if caught in the
path of a closing window. Never
leave the Remote Keyless Entry
(RKE) transmitter or keys in a
vehicle with children. When there
are children in the rear seat, use
the window lockout button to(Continued)
Warning (Continued)
prevent operation of the windows.
SeeKeys (Key Access) 09or
Keys (Keyless Access) 012.
The power windows work when the
ignition is on, in ACC/ACCESSORY,
or when Retained Accessory Power
(RAP) is active. See Retained
Accessory Power (RAP) 0217.
Using the window switch, press to
open or pull to close the window. The windows may be temporarily
disabled if they are used repeatedly
within a short time.
Window Lockout
With Power Folding Mirrors,
Without Similar
This feature stops the rear door
passenger window switches from
working except from the driver
position.
Press
2to engage the rear
window lockout feature. The
indicator light is on when engaged.
Press
2again to disengage.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Keys, Doors, and Windows 51
Rear Windows
Power Sliding Rear Window
If equipped, the power sliding rear
window works when the ignition has
been turned on or to ACC/
ACCESSORY, or Retained
Accessory Power (RAP) must be
active. SeeRetained Accessory
Power (RAP) 0217.
. Press the switch to open the
window.
. Pull the switch to close the
window. The power sliding rear window
cannot be operated manually.
Sun Visors
Pull the sun visor down to block
glare. If equipped, detach the sun
visor from the center mount to pivot
to the side window or to extend
along the rod.
If equipped, there is a lighted mirror
on the sun visor. Lift the cover
to open.
Roof
Sunroof
1. SLIDE Switch
2. TILT Switch
If equipped, the sunroof operates
when the ignition is on or in ACC/
ACCESSORY, or when Retained
Accessory Power (RAP) is active.
See
Retained Accessory Power
(RAP) 0217.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
52 Keys, Doors, and Windows
Slide Switch
Express-Open/Express-Close :To
express-open the sunroof, fully
press and release
I(1). Press and
release
I(1) again to stop the
movement. To express-close the
sunroof, fully press and release
K
(1). Press and releaseK(1)
again to stop the movement.
Open/Close (Manual Mode) : To
open the sunroof, press and hold
I
(1). ReleaseI(1) to stop the
movement. Press and hold
K(1)
to close the sunroof. Release
K
(1) to stop the movement.
Tilt Switch
Vent : From the closed position,
press
J(2) to vent the sunroof.
Press
K(2) to close the vent.
When the sunroof is opened, an air
deflector will automatically raise.
The air deflector will retract when
the sunroof is closed. The sunroof also has a sunshade,
which can be pulled forward to block
sun rays. The sunshade must be
opened and closed manually.
Automatic Reversal System
The sunroof has an automatic
reversal system that is only active
when the sunroof is operated in
express-close mode.
If an object is in the path while
express-closing, the reversal system
will detect an object, stop, and open
the sunroof again.
If frost or other conditions prevent
closing, override the feature by
closing the sunroof in manual mode.
To stop movement, release
K(1).
Dirt and debris may collect on the
sunroof seal or in the track. This
could cause an issue with sunroof
operation or noise. It could also plug
the water drainage system.
Periodically open the sunroof and
remove any obstacles or loose
debris. Wipe the sunroof seal and
roof sealing area using a clean
cloth, mild soap, and water. Do not
remove grease from the sunroof
tracks.
If water is seen dripping into the
water drainage system, this is
normal.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 217
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Retained Accessory
Power (RAP)
When the ignition is turned from on
to off, the following features (if
equipped) will continue to function
for up to 10 minutes, or until the
driver door is opened. These
features will also work when the
ignition is in RUN or ACC/
ACCESSORY:
.Infotainment System
. Power Windows (during RAP
this functionality will be lost
when any door is opened)
. Sunroof (during RAP this
functionality will be lost when
any door is opened)
. Auxiliary Power Outlet
. Audio System
. OnStar System
Shifting Into Park
{Warning
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. With four-wheel drive,
if the transfer case is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever
is in P (Park). Be sure the transfer
case is in a drive gear. If towing a
trailer, see Driving Characteristics
and Towing Tips 0287.
1. Hold the brake pedal down, then set the parking brake. See
Electric Parking Brake 0233. 2. Move the shift lever into the
P (Park) position by pulling the
shift lever toward you and
moving it up as far as it will go.
3. Be sure the transfer case (if equipped) is in a drive
gear –not in N (Neutral).
4. Turn the ignition off. For Key Access, push the ignition key
in, towards the steering column
and then turn the ignition off.
5. For Key Access, remove the key and take it with you. If you
can leave the vehicle with the
ignition key in your hand, the
vehicle is in P (Park).
For Keyless Access, take the
Remote Keyless Entry (RKE)
transmitter with you.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
378 Vehicle Care
FusesUsage
F30 Sensing and diagnostic module/
Parking brake
F31 Body control module 4
F32 Special equipment option/Data link
connection
F33 Body control module 8
F34 Cargo lamp
F40 CGM
F41 Infotainment 1
F42 TCP
F43 –
F44 AVM
F45 Body control module 2
F46 Heating, ventilation, and air conditioning/
Battery 1
F47 Instrument panel cluster/Battery
F48 Transmission control module Fuses
Usage
F49 Body control module 1
F50 –
F51 Battery 1
F52 Battery 2
F53 –
F54 Sunroof
F55 Driver power seat
F56 DC DC TRANS 1
F57 DC DC TRANS 2
F58 Infotainment 2
Circuit
Breakers Usage
1 Accessory power outlet 2
2 Accessory power outlet 1/Cigarette
Lighter
3 Accessory power outlet 3
4 Accessory power outlet 4 Relays
Usage
K1 Run/Crank
K2 Retained accessory power/Accessory 1
K4 Retained accessory power/Accessory 2
K5 –

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
444 Service and Maintenance
fittings, lubricate the suspension
and steering components every
other oil change for normal
usage and every oil change for
severe usage.
. Inspect power steering for
proper attachment, connections,
binding, leaks, cracks,
chafing, etc.
. Visually inspect drive shafts for
excessive wear, lubricant leaks
or damage including: tube dents,
cracks, constant velocity joint or
universal joint looseness,
cracked or missing boots, loose
or missing boot clamps, center
bearing excessive looseness,
missing or loose fasteners.
. Check restraint system
components. See Safety System
Check 071.
. Visually inspect fuel system for
damage or leaks.
. Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts. .
Lubricate body components. See
Exterior Care 0429.
. Check starter switch. See Starter
Switch Check 0363.
. Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function Check
0363.
. Check ignition transmission lock.
See Ignition Transmission Lock
Check 0363.
. Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check
0 364.
. Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
. Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. If the hold
open is low, service the gas
strut. See Gas Strut(s) 0365. .
Inspect sunroof track and seal,
if equipped. See Sunroof051.
. Verify spare tire key lock
operation and lubricate as
needed. See Tire Changing
0 407.
. Visually inspect the spare tire to
ensure that it is tightly stowed
under the vehicle. Push, pull,
and try to turn the tire. If the
spare tire moves, tighten as
necessary. See Tire Changing
0 407.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 497
Roadside AssistanceProgram . . . . . . . . . . . . . . . . . . . . . . . 467
Roof Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . 51
Rotation, Tires . . . . . . . . . . . . . . . . . . 396
Routing, Engine Drive Belt . . . . . . 462
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . . . . 220
S
Safety Defects ReportingCanadian Government . . . . . . . . 473
General Motors . . . . . . . . . . . . . . . 474
U.S. Government . . . . . . . . . . . . . 473
Safety Locks . . . . . . . . . . . . . . . . . . . . . 27
Safety System Check . . . . . . . . . . . . 71
Scheduling Appointments . . . . . . . 468
Seat Belts . . . . . . . . . . . . . . . . . . . . . . . 65 Care . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Extender . . . . . . . . . . . . . . . . . . . . . . . . 71
How to Wear Seat BeltsProperly . . . . . . . . . . . . . . . . . . . . . . . 66
Lap-Shoulder Belt . . . . . . . . . . . . . . 68
Reminders . . . . . . . . . . . . . . . . . . . . 136
Replacing after a Crash . . . . . . . . 72
Use During Pregnancy . . . . . . . . . . 70
Seats Adjustment, Front . . . . . . . . . . . . . . . 55 Seats (cont'd)
Center Seat . . . . . . . . . . . . . . . . . . . . 56
Head Restraints . . . . . . . . . . . . . . . . 54
Heated and Ventilated Front . . . . 61
Heated, Rear . . . . . . . . . . . . . . . . . . . 64
Lumbar Adjustment, Front . . . . . . 57
Memory . . . . . . . . . . . . . . . . . . . . . . . . . 59
Power Adjustment, Front . . . . . . . 56
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Reclining Seatbacks . . . . . . . . . . . . 57
Underseat Storage . . . . . . . . . . . .114
Securing Child Restraints . . . . . . . . . . .105, 108, 109
Security
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 147
OnStar . . . . . . . . . . . . . . . . . . . . . . . 479
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 37
Vehicle Alarm . . . . . . . . . . . . . . . . . . . 37
Service . . . . . . . . . . . . . . . . . . . . . . . . . 184 Accessories andModifications . . . . . . . . . . . . . . . . 329
Climate Control System . . . . . . . 177
Doing Your Own Work . . . . . . . . 330
Maintenance Records . . . . . . . . 457
Maintenance, General Information . . . . . . . . . . . . . . . . . . 440
Parts Identification . . . . . . . . . . . . 458
Scheduling Appointments . . . . . 468 Service Electric Parking
Brake Light . . . . . . . . . . . . . . . . . . . . 141
Services Special Application . . . . . . . . . . . 449
Servicing the Airbag . . . . . . . . . . . . . 83
Shift Lock Control Function Check, Automatic
Transmission . . . . . . . . . . . . . . . . . . 363
Shifting Into Park . . . . . . . . . . . . . . . . . . . . . . 217
Out of Park . . . . . . . . . . . . . . . . . . . 218
Side Blind Zone Alert (SBZA) . . . 274
Signals, Turn and Lane-Change . . . . . . . . . . . . . . . . . 170
Snow Plow . . . . . . . . . . . . . . . . . . . . . 323
Special Application Services . . . . 449
Specifications and Capacities . . . . . . . . . . . . . . . . . . . . . 459
Speedometer . . . . . . . . . . . . . . . . . . . 131
Start Assist, Hill . . . . . . . . . . . . . . . . . 235
Start Vehicle, Remote . . . . . . . . . . . 24
Starter Switch Check . . . . . . . . . . . 363
Starting the Engine . . . . . . . . . . . . . 212
Steering . . . . . . . . . . . . . . . . . . . . . . . . 188 Fluid, Power . . . . . . . . . . . . . . . . . . 354
Heated Wheel . . . . . . . . . . . . . . . . 120
Wheel Adjustment . . . . . . . . . . . . .119
Wheel Controls . . . . . . . . . . . . . . . 120