2020 GMC SIERRA DENALI key battery

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Vehicle Care 349
Automatic Coolant Service Fill
Instructions (L3B Engine)
See 3.0L Duramax Diesel
supplement for the diesel engine
procedure.
If equipped, this feature assists in
filling and removing air from the
cooling system after service of
components or when coolant is
added after being too low.
To activate the fill and air removal
process:1. With a cold system, add coolant to the indicated mark
on the surge tank.
2. Replace the cap on the surge tank.
3. Connect the vehicle to a battery charger.
4. Set the ignition to Service or Accessory Mode. See Ignition
Positions (Keyless Access)
0 208 or
Ignition Positions (Key Access)
0 210.
5. Turn off the air conditioning. 6. Set the parking brake.
7. At the same time, press the
accelerator and the brake for
automatic transmission
vehicles for two seconds, then
release.
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
two minutes, and repeat Steps 3–7.
Listen for pump activation and
movement of the control valves
while watching the level of the
coolant in the surge tank. If the tank
empties, turn the ignition off,
carefully remove the surge tank cap,
refill to the indicated mark, and
repeat Steps 3–6. The fill and air
removal process will run for
approximately 10 minutes.
How to Add Coolant to the
Coolant Surge Tank for
Gasoline Engines Except L3B
If the vehicle has a diesel engine,
see “Cooling System” in the
Duramax diesel supplement for the
proper coolant fill procedure.
{Warning
Spilling coolant on hot engine
parts can burn you. Coolant
contains ethylene glycol and it will
burn if the engine parts are hot
enough.
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Vehicle Care 359
{Warning
WARNING:Battery posts,
terminals, and related
accessories contain lead and lead
compounds, chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Batteries also
contain other chemicals known to
the State of California to cause
cancer. WASH HANDS AFTER
HANDLING. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition
65 Warning 0329 and the back
cover.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See Jump Starting -
North America 0419 for tips on
working around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Negative Battery Cable
Disconnection
{Warning
Before disconnecting the negative
battery cable, turn off all features,
turn the ignition off, and remove
the key, if equipped, from the
vehicle. If this is not done, you or
others could be injured, and the
vehicle could be damaged.
Caution
If the battery is disconnected with
the ignition on or the vehicle in
Retained Accessory Power
(RAP), the OnStar back-up
battery will be permanently
discharged and will need to be
replaced.
1. Make sure the lamps, features, and accessories are turned off.
2. Turn the ignition off and remove the key, if equipped.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
Vehicle Care 427
Warning (Continued)
negative battery cable and cover
the negative battery post and
cable with a non-conductive
material. If the battery is left
connected or the battery cable
contacts the post, the Electric
Parking Brake may activate
during towing, which could cause
a crash.
8. Disconnect the negative (–) battery cable. See “Negative
Battery Cable Disconnection”
in Battery - North America
0 358.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked,
vehicle damage may occur. 10. Move the steering wheel to
make sure the steering column
is unlocked.
11. If the vehicle has an ignition key, keep it in the towed
vehicle in ACC/ACCESSORY
to prevent the steering column
from locking. If the vehicle is
equipped with Keyless Access,
keep the RKE transmitter
outside of the vehicle and
manually lock the doors.
Access the vehicle by using
the key in the door lock. See
Door Locks 026.
Disconnecting the Towed Vehicle
Before disconnecting from the tow
vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North
America 0358. 3. Turn on the ignition with the
engine off. For vehicles with a
key, turn the ignition to ON/
RUN with the engine off. If the
vehicle is equipped with
Keyless Access, with your foot
off the brake pedal, press and
hold ENGINE START/STOP for
five seconds until the green
light comes on in the button.
See Ignition Positions (Keyless
Access) 0208 or
Ignition Positions (Key Access)
0 210.
4. Set the parking brake. See Electric Parking Brake 0233.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral).
7. Shift the transfer case to 2
m
(Two-Wheel Drive High). When
the shift to 2
m(Two-Wheel
Drive High) is complete, the
light in the instrument cluster
will stop flashing and stay lit.
See Four-Wheel-Drive Light
0 141.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 8/27/19
OnStar 477
Press=to:
. Open the OnStar app on the
infotainment display. See the
infotainment manual for
information on how to use the
OnStar app.
Or
. Give OnStar Turn-by-Turn
Navigation voice commands.
. Obtain and customize the Wi-Fi
hotspot name or SSID and
password, if equipped.
Press
Qto connect to an
Advisor to:
. Verify account information or
update contact information.
. Get driving directions.
. Receive a Diagnostic check of
the vehicle's key operating
systems.
. Receive Roadside Assistance.
. Manage Wi-Fi Settings,
if equipped. Press
>to get a priority connection
to an OnStar Advisor available
24/7 to:
. Get help for an emergency.
. Be a Good Samaritan or
respond to an AMBER Alert.
. Get assistance in severe
weather or other crisis situations
and find evacuation routes.OnStar Services
Emergency
Emergency Services require an
active safety and security plan. With
Automatic Crash Response, built-in
sensors can automatically alert a
specially trained OnStar Advisor
who is immediately connected in to
the vehicle to help.
Press
>for a priority connection to
an OnStar Advisor who can contact
emergency service providers, direct
them to your exact location, and
relay important information.
With OnStar Crisis Assist, specially
trained Advisors are available
24 hours a day, 7 days a week, to
provide a central point of contact,
assistance, and information during a
crisis.
With Roadside Assistance, Advisors
can locate a nearby service provider
to help with a flat tire, a battery
jump, or an empty gas tank.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
492 Index
Glove Box . . . . . . . . . . . . . . . . . . . . . . 112
GM Mobility ReimbursementProgram . . . . . . . . . . . . . . . . . . . . . . . 465
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 367
Hazard Warning Flashers . . . . . . . 169
Head Restraints . . . . . . . . . . . . . . . . . 53
Head-up Display . . . . . . . . . . . . . . . . 152
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 366
Automatic . . . . . . . . . . . . . . . . . . . . . 168
Bulb Replacement . . . . . . . . . . . . 367
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . 168
Flash-to-Pass . . . . . . . . . . . . . . . . . 168
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . . . 367
High-Beam On Light . . . . . . . . . . 146
High/Low Beam Changer . . . . . 167
Lamps On Reminder . . . . . . . . . 146
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . 63
Steering Wheel . . . . . . . . . . . . . . . .119
Heated and Ventilated Front
Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Heated Mirrors . . . . . . . . . . . . . . . . . . . 43 Heater
Engine . . . . . . . . . . . . . . . . . . . . . . . . 215
Heating . . . . . . . . . . . . . . . . . . . . 177, 179
High-Beam On Light . . . . . . . . . . . . 146
High-Speed Operation . . . . . . . . . . 389
Hill and Mountain Roads . . . . . . . . 197
Hill Descent Control (HDC) . . . . . 237
Hill Descent Control Light . . . . . . . 141
Hill Start Assist (HSA) . . . . . . . . . . 235
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 65
HVAC . . . . . . . . . . . . . . . . . . . . . . 177, 179
I
Ignition Positions . . . . . . . . . . 208, 210
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 363
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 37
Indicator Pedestrian Ahead . . . . . . . . . . . . 142
Vehicle Ahead . . . . . . . . . . . . . . . . 142
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . . . 86
Information
Publication Ordering . . . . . . . . . . 471
Infotainment . . . . . . . . . . . . . . . . . . . . 176 Infotainment System . . . . . . . . . . . . 475
Instrument Cluster . . . . . . . . . . . . . . 126
Instrument Panel Overview . . . . . . . 5
Interior Rearview Mirrors . . . . . . . . . 44
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jump Starting - North
America . . . . . . . . . . . . . . . . . . . . . . . 419
K
Keyless EntryRemote (RKE) System . . . . . 13, 16
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . .9, 12
L
Labeling, Tire Sidewall . . . . . . . . . . 381
Lamps Daytime Running (DRL) . . . . . . 168
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 172
Exterior Cargo . . . . . . . . . . . . . . . . 171
Exterior Controls . . . . . . . . . . . . . . 165
Exterior Lamps OffReminder . . . . . . . . . . . . . . . . . . . 167
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . . . . 174
License Plate . . . . . . . . . . . . . . . . . 369
Malfunction Indicator (Check Engine) . . . . . . . . . . . . . 137

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 8/27/19
Index 495
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Passenger Sensing System . . . . . 77
Pedestrian Ahead Indicator . . . . . 142
Perchlorate Materials Requirements, California . . . . . . 329
Personalization
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 156
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . . . . . 326
Power
Door Locks . . . . . . . . . . . . . . . . . . . . . 27
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Outlets . . . . . . . . . . . . . . . . . . . . . . . 121
Protection, Battery . . . . . . . . . . . . 174
Retained Accessory (RAP) . . . 216
Seat Adjustment . . . . . . . . . . . . . . . . 55
Steering Fluid . . . . . . . . . . . . . . . . . 354
Windows . . . . . . . . . . . . . . . . . . . . . . . 47
Power Assist Steps . . . . . . . . . . . . . . 34
Pregnancy, Using Seat Belts . . . . 69
Privacy Vehicle Data Recording . . . . . . . 473
Program Courtesy Transportation . . . . . . 468
Prohibited Fuels . . . . . . . . . . . . . . . . 281 Proposition
65 Warning,
California . . . . . . . . . . . .329, 358, 419,
Back Cover
Publication Ordering Information . . . . . . . . . . . . . . . . . . . . 471
R
Radio Frequency Statement . . . . 472
Reading Lamps . . . . . . . . . . . . . . . . . 173
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . 362Locking . . . . . . . . . . . . . . . . . . . . . . . 242
Rear Camera Mirror . . . . . . . . . . . . . 45
Rear Seats . . . . . . . . . . . . . . . . . . . . . . 62 Heated . . . . . . . . . . . . . . . . . . . . . . . . . 63
Rear Storage . . . . . . . . . . . . . . . . . . . 113
Rear Vision Camera (RVC) . . . . . 257
Rear Windows . . . . . . . . . . . . . . . . . . . 49
Rearview Mirrors . . . . . . . . . . . . . . . . 44 Automatic Dimming . . . . . . . . . . . . . 44
Reclining Seatbacks . . . . . . . . . . . . . 56
Recommended
Fuel . . . . . . . . . . . . . . . . . . . . . 280, 281
Recommended Fluids and Lubricants . . . . . . . . . . . . . . . . . . . . . 452
Records
Maintenance . . . . . . . . . . . . . . . . . . 456 Recreational Vehicle Towing . . . . 424
Reimbursement Program,
GM Mobility . . . . . . . . . . . . . . . . . . . 465
Remote Keyless Entry (RKE) System . . . . . . . . . . . . . . 13, 16
Remote Vehicle Start . . . . . . . . . . . . 25
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . 83
Maintenance . . . . . . . . . . . . . . . . . . 454
Replacing Airbag System . . . . . . . . 83
Replacing LATCH System Parts after a Crash . . . . . . . . . . . . 104
Replacing Seat Belt System Parts after a Crash . . . . . . . . . . . . . 71
Reporting Safety Defects Canadian Government . . . . . . . . 472
General Motors . . . . . . . . . . . . . . . 473
U.S. Government . . . . . . . . . . . . . 472
Restraints Where to Put . . . . . . . . . . . . . . . . . . . 90
Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . . . 216
Reverse Tilt Mirrors . . . . . . . . . . . . . . 44
Ride Control Systems Enhanced Traction
System (ETS) . . . . . . . . . . . . . . . 242