2020 GMC SIERRA overheating

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 351
6. Verify coolant level after theengine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–6.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away. The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See
Engine Coolant
Temperature Gauge 0134.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 467.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
2.7L L4, 4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If the engine or transmission detects
an impending hot fluid condition,
then the transmission may force
upshifts to limit temperatures.
Downshifts may also be prevented
in this instance. Normal operation
may continue unless the display
indicates there is a hot condition
and engine should be idled.
If Steam is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 379
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. SeeVehicle Load
Limits 0200.
(Continued)
Warning (Continued)
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold.
.Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact —such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued)
Warning (Continued)
.Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc.
.Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires.
.Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
All-Season Tires
This vehicle may come with
all-season tires. These tires are
designed to provide good overall

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 387
Speed Rating:An
alphanumeric code assigned to
a tire indicating the maximum
speed at which a tire can
operate.
Traction
:The friction between
the tire and the road surface.
The amount of grip provided.
Tread
:The portion of a tire that
comes into contact with
the road.
Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1.6 mm (1/
16 in) of tread remains. See
When It Is Time for New Tires
0 398.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that provides
consumers with ratings for a
tire's traction, temperature, and
treadwear. Ratings are
determined by tire
manufacturers using government testing procedures.
The ratings are molded into the
sidewall of the tire. See
Uniform
Tire Quality Grading 0401.
Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated
cargo load. See Vehicle Load
Limits 0200.
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a
vehicle showing the vehicle
capacity weight and the original
equipment tire size and
recommended inflation pressure.
See “Tire and Loading
Information Label” underVehicle
Load Limits 0200.
Tire Pressure
Tires need the correct amount of
air pressure to operate
effectively.
{Warning
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in:
.Tire overloading and
overheating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in:
.Unusual wear.
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 491
DiagnosticsConnected Services . . . . . . . . . . 487
Differential, Limited-Slip . . . . . . . . 242
Distracted Driving . . . . . . . . . . . . . . . 187
Dome Lamps . . . . . . . . . . . . . . . . . . . 172
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . 148
Delayed Locking . . . . . . . . . . . . . . . . 26
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Power Locks . . . . . . . . . . . . . . . . . . . . 26
Drive Belt Routing, Engine . . . . . . 462
Driver Assistance Systems . . . . . 256
Driver Information
Center (DIC) . . . . . . . . . . . . . 148, 149
Driver Mode Control . . . . . . . . . . . . 238
Driver Mode Control Light . . . . . . 145
Driving Assistance Systems . . . . . . . . . . 268
Better Fuel Economy . . . . . . . . . 186
Characteristics andTowing Tips . . . . . . . . . . . . . . . . . 287
Defensive . . . . . . . . . . . . . . . . . . . . . 187
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 188
Hill and Mountain Roads . . . . . . 197
If the Vehicle is Stuck . . . . . . . . . 199
Loss of Control . . . . . . . . . . . . . . . 190
Off-Road . . . . . . . . . . . . . . . . . . . . . 191
Off-Road Recovery . . . . . . . . . . . 190 Driving (cont'd)
Vehicle Load Limits . . . . . . . . . . . 200
Wet Roads . . . . . . . . . . . . . . . . . . . 196
Winter . . . . . . . . . . . . . . . . . . . . . . . . 197
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 179
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 282
Electric Brake Boost . . . . . . . . . . . . 232
Electric Parking Brake . . . . . . . . . . 233
Electric Parking Brake Light . . . . 141
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 322
Electrical System Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 371
Fuses and Circuit Breakers . . . 370
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 374, 376
Overload . . . . . . . . . . . . . . . . . . . . . 370
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . 144
Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . 478
Engine Air Cleaner/Filter . . . . . . . . . . . . . 344 Engine (cont'd)
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 138
Compartment Overview . . . . . . . 332
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 134
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 145
Cooling System . . . . . . . . . . . . . . . 346
Drive Belt Routing . . . . . . . . . . . . 462
Exhaust . . . . . . . . . . . . . . . . . . . . . . 220
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Heater . . . . . . . . . . . . . . . . . . . . . . . . 215
Oil Life System . . . . . . . . . . . . . . . 341
Oil Pressure Gauge . . . . . . . . . . 133
Oil Pressure Light . . . . . . . . . . . . 146
Overheated Protection Operating Mode . . . . . . . . . . . . . 352
Overheating . . . . . . . . . . . . . . . . . . 351
Power Messages . . . . . . . . . . . . . 156
Running While Parked . . . . . . . . 220
Starting . . . . . . . . . . . . . . . . . . . . . . . 212
Engine Air Filter Life System . . . . 343
Entry Lighting . . . . . . . . . . . . . . . . . . . 173
Equipment, Towing . . . . . . . . . . . . . 296
Event Data Recorders . . . . . . . . . . 475
Exit Lighting . . . . . . . . . . . . . . . . . . . . 173
Extended Parking . . . . . . . . . . . . . . . 219

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
Index 495
Maintenance Schedule (cont'd)Recommended Fluids and
Lubricants . . . . . . . . . . . . . . . . . . . 453
Transfer Case . . . . . . . . . . . . . . . . 227
Malfunction Indicator Lamp . . . . . 138
Manual Mirrors . . . . . . . . . . . . . . . . . . 41
Manual Mode . . . . . . . . . . . . . . . . . . . 224
Manual Windows . . . . . . . . . . . . . . . . 49
Memory Seats . . . . . . . . . . . . . . . . . . . 59
Messages Engine Power . . . . . . . . . . . . . . . . 156
Vehicle . . . . . . . . . . . . . . . . . . . . . . . 156
Vehicle Speed . . . . . . . . . . . . . . . . 156
Mirror
Rear Camera . . . . . . . . . . . . . . . . . . . 46
Mirrors Automatic Dimming . . . . . . . . . . . . . 44
Automatic DimmingRearview . . . . . . . . . . . . . . . . . . . . . . 46
Blind Spot . . . . . . . . . . . . . . . . . . . . . . 44
Convex . . . . . . . . . . . . . . . . . . . . . . . . . 40
Folding . . . . . . . . . . . . . . . . . . . . . . . . . 43
Heated . . . . . . . . . . . . . . . . . . . . . . . . . 44
Manual . . . . . . . . . . . . . . . . . . . . . . . . . 41
Manual Rearview . . . . . . . . . . . . . . . 46
Power . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Tilt in Reverse . . . . . . . . . . . . . . . . . . 45
Trailer Tow . . . . . . . . . . . . . . . . . . . . . . 41 Mirrors, Interior Rearview . . . . . . . . 46
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Driver Control . . . . . . . . . . . . . . . . . 238
Monitor System, Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 389
N
NavigationConnected Services . . . . . . . . . . 485
New Vehicle Break-In . . . . . . . . . . . 208
Noise Control System . . . . . . . . . . 362
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . 132 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Off-Road . . . . . . . . . . . . . . . . . . . . . . . 191 Driving . . . . . . . . . . . . . . . . . . . . . . . . 191
Recovery . . . . . . . . . . . . . . . . . . . . . 190
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . 339
Engine Oil Life System . . . . . . . 341
Engine Oil Pressure Gauge . . . 133
Pressure Light . . . . . . . . . . . . . . . . 146
Older Children, Restraints . . . . . . . 85
Online Owner Center . . . . . . . . . . . 466
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . 476
OnStar Additional Information . . . . . . . . . . . . . . . . . . . . 479
OnStar Emergency . . . . . . . . . . . . . 478 OnStar Overview . . . . . . . . . . . . . . . 477
OnStar Security . . . . . . . . . . . . . . . . 479
Operating Mode
Overheated EngineProtection . . . . . . . . . . . . . . . . . . . 352
Operation Fog Lamps . . . . . . . . . . . . . . . . . . . 170
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . 122
Overheated Engine Protection Operating Mode . . . . 352
Overheating, Engine . . . . . . . . . . . . 351
Overview Instrument Panel . . . . . . . . . . . . . . . . 5
P
ParkShifting Out of . . . . . . . . . . . . . . . . 218
Park Assist . . . . . . . . . . . . . . . . . . . . . 257
Parking Brake and P (Park)
Mechanism Check . . . . . . . . . . 364
Extended . . . . . . . . . . . . . . . . . . . . . 219
Over Things That Burn . . . . . . . 219
Parking or Backing Assistance Systems . . . . . . . . . . 257
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . 137