heater GMC SIERRA 2021 User Guide

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 339
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. SeeRoadside Assistance Program
0 431.
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.
If No Steam is Coming from the Engine
Compartment
The ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious problem.
The 2.7L L4 engine will shut down
automatically if the ENGINE OVERHEATED
STOP ENGINE message displays.
If there is an engine overheat warning, but
no steam is seen or heard, the problem may
not be too serious. Sometimes the engine
can get a little too hot when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.
.Tows a trailer; see Trailer Towing0293.
If the ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE
message appears with no sign of steam, try
this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan
speed. Open the windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or N (Neutral) and
let the engine idle.
If the temperature overheat gauge is no
longer in the overheat zone or an overheat
warning no longer displays, the vehicle can
be driven. Continue to drive the vehicle
slowly for about 10 minutes. Keep a safe
vehicle distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have the
cooling system checked for proper fill and
function.
If the warning continues, pull over, stop, and
park the vehicle right away.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 451
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145
DoorAjar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 427
Driver
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Driver Assistance Systems . . . . . . . . . . . . . . . 265
Driver Information Center (DIC) . . . . . . 124, 125
Driver Mode Control . . . . . . . . . . . . . . . . . . . . . . 251
Driver Mode Control Light . . . . . . . . . . . . . . . . 121
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 274
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 212
Characteristics and Towing Tips . . . . . . . . 288
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Hill and Mountain Roads . . . . . . . . . . . . . . 219
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 221
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 214
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 222
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Dual Automatic Climate Control
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
E
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Electric Brake Boost . . . . . . . . . . . . . . . . . . . . . . 246
Electric Parking Brake . . . . . . . . . . . . . . . . . . . . 247
Electric Parking Brake Light . . . . . . . . . . . . . . . 117
Electrical Equipment, Add-On . . . . . . . . . . . . .318
Electrical System
Engine Compartment Fuse Block . . . . . . . 353
Fuses and Circuit Breakers . . . . . . . . . . . . . 353
Instrument Panel Fuse Block . . . . . . 357, 358
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 334
Check Light (Malfunction Indicator) . . . . . 115
Compartment Overview . . . . . . . . . . . . . . . . 325
Coolant Temperature Gauge . . . . . . . . . . . . 112
Coolant Temperature Warning Light . . . . 121
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 335
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 427 Engine (cont'd)
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 332
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . 111
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . 122
Overheated Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . 340
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 338
Power Messages . . . . . . . . . . . . . . . . . . . . . . . . 131
Running While Parked . . . . . . . . . . . . . . . . . 238
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Engine Air Filter Life System . . . . . . . . . . . . . 333
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 296
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 438
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . 238
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 59
Exterior Cargo Lamps . . . . . . . . . . . . . . . . . . . . 144
Exterior Lamp Controls . . . . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . . . .147

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
Index 453
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Hazard Warning Flashers . . . . . . . . . . . . . . . . .142
HD Radio Technology . . . . . . . . . . . . . . . . . . . . 156
Head Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Head-up Display . . . . . . . . . . . . . . . . . . . . . . . . . .128
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . 350
Daytime Running Lamps (DRL) . . . . . . . . . . 141
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Headlamps, Front Turn Signal,Sidemarker, and Parking Lamps . . . . . . 350
High-Beam On Light . . . . . . . . . . . . . . . . . . . 123
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Lamps On Reminder . . . . . . . . . . . . . . . . . . . 123
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . 100
Heated and Ventilated Front Seats . . . . . . . .52
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 206
High-Beam On Light . . . . . . . . . . . . . . . . . . . . . . 123
Hill and Mountain Roads . . . . . . . . . . . . . . . . 219
Hill Descent Control (HDC) . . . . . . . . . . . . . . . 250 Hill Descent Control Light . . . . . . . . . . . . . . . . . 119
Hill Start Assist (HSA) . . . . . . . . . . . . . . . . . . . . 248
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
How to Wear Seat Belts Properly . . . . . . . . . .55
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204, 206
I
If the System Needs Service . . . . . . . . . . . . . . 175
Ignition Positions . . . . . . . . . . . . . . . . . . . 229, 230
Ignition Transmission Lock Check . . . . . . . . 347
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Indicator
Pedestrian Ahead . . . . . . . . . . . . . . . . . . . . . . . 119
Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Infants and Young Children, Restraints . . . . .72
Information Publication Ordering . . . . . . . . . . . . . . . . . . . 435
Infotainment System . . . . . . . . . . . . . . . . . . . . 439
Instrument Cluster . . . . . . . . . . . . . . . . . . . . . . . 106
Instrument Panel Overview . . . . . . . . . . . . . . . . 4
Interior Rearview Mirrors . . . . . . . . . . . . . . . . . 38
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 148
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Jump Starting - North America . . . . . . . . . . . 391
K
Keyless Entry Remote (RKE) System . . . . . . . . . . . . . . . . 10, 13
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7, 9
L
Labeling, Tire Sidewall . . . . . . . . . . . . . . . . . . . 362
Lamps Auxiliary Roof Mounted Lamp . . . . . . . . . 144
Daytime Running (DRL) . . . . . . . . . . . . . . . . . 141
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Exterior Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 144
Exterior Controls . . . . . . . . . . . . . . . . . . . . . . . 139
Exterior Lamps Off Reminder . . . . . . . . . . . 141
Exterior Lighting Battery Saver . . . . . . . . 147
License Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Malfunction Indicator (CheckEngine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
On Reminder . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Lane Change Alert (LCA) . . . . . . . . . . . . . . . . . 280
Lane Keep Assist (LKA) . . . . . . . . . . . . . . . . . . . .281
Lane Keep Assist Light . . . . . . . . . . . . . . . . . . . . 119
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . . . . . . .57
LATCH System Replacing Parts after a Crash . . . . . . . . . . . 88
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77