2018 GMC SIERRA check engine light

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
368 Vehicle Care
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or parts are improperly
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview
0345 for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down: .
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.
. A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged. (Continued)
Warning (Continued)
Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light 0152.
Brake fluid absorbs water over time.
Replace brake fluid at the specified
intervals to prevent increased
stopping distance. See Maintenance
Schedule 0448.
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview 0345.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
428 Vehicle Care
{Warning
Using a match near a battery can
cause battery gas to explode.
People have been hurt doing this,
and some have been blinded.
Use a flashlight if you need more
light.
Battery fluid contains acid that
can burn you. Do not get it on
you. If you accidentally get it in
your eyes or on your skin, flush
the place with water and get
medical help immediately.
{Warning
Fans or other moving engine
parts can injure you badly. Keep
your hands away from moving
parts once the engine is running.6. Check that the jumper cables
do not have loose or missing
insulation. If they do, you could
get a shock. The vehicles
could be damaged too.
Before you connect the cables,
here are some basic things you
should know. Positive (+) will
go to positive (+) or to a remote
positive (+) terminal if the
vehicle has one. Negative (−)
will go to a heavy, unpainted
metal engine part or to a
remote negative (−) terminal if
the vehicle has one.
Do not connect positive (+) to
negative (−) or you will get a
short that would damage the
battery and maybe other parts
too. And do not connect the
negative (−) cable to the
negative (−) terminal on the
dead battery because this can
cause sparks.
5.3L Shown, 4.3L, 6.0L, 6.2L, and
6.6L Similar
7. Connect the red positive (+) cable to the positive (+)
terminal of the vehicle with the
dead battery.
8. Do not let the other end touch metal. Connect it to the
positive (+) terminal of the
good battery. Use a remote
positive (+) terminal if the
vehicle has one.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
454 Service and Maintenance
Battery
The 12-volt battery supplies power
to start the engine and operate any
additional electrical accessories.
.To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of
cracking or splitting.
. Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary. Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
. Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle’s systems
and components. See
Recommended Fluids and
Lubricants 0456 for GM approved
fluids.
. Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled. Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
. With a multi-point inspection,
your dealer can check the lamps
and note any concerns.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 491
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 343
Accessory Power . . . . . . . . . . . . . . . 260
Active Fuel Management . . . . . . . 264
Add-On Electrical Equipment . . . 336
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . 337
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . 485
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . 453
Adjustable Throttle and Brake Pedal . . . . . . . . . . . . . . . . . . . 256
Adjustments Lumbar, Front Seats . . . . . . . . . . . . 60
Agreements Trademarks and License . . . . . 218
Air Cleaner/Filter, Engine . . . . . . . 358
Air Conditioning . . . . . .224, 226, 228
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . 232
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 231
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 91
How Does an AirbagRestrain? . . . . . . . . . . . . . . . . . . . . . 82
Passenger Sensing System . . . . 86 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 82
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 82
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 80
Where Are the Airbags? . . . . . . . . 78
Airbags
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 90
Light On-Off . . . . . . . . . . . . . . . . . . 147
On-Off Light . . . . . . . . . . . . . . . . . . 147
On-Off Switch . . . . . . . . . . . . . . . . . . 84
Passenger Status Indicator . . . 149
Readiness Light . . . . . . . . . . . . . . 147
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 90
System Check . . . . . . . . . . . . . . . . . . 77
Alarm Vehicle Security . . . . . . . . . . . . . . . . 44
All-Season Tires . . . . . . . . . . . . . . . . 389
All-Terrain Tires . . . . . . . . . . . . . . . . . 391
AM-FM Radio . . . . . . . . . . . . . . . . . . . 190
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . 194
Multi-band . . . . . . . . . . . . . . . . . . . . 194
Antilock Brake System (ABS) . . . 280

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 493
California (cont'd)Perchlorate Materials
Requirements . . . . . . . . . . . . . . . 343
California
Proposition
65 Warning . . . . . . . . . .343, 369, 426, Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 461
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 264
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . 43
Winter Driving . . . . . . . . . . . . . . . . 245
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . 126
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 183
Caution, Danger, and Warning . . . . 3
CD Player . . . . . . . . . . . . . . . . . . . . . . 195
Center Console Storage . . . . . . . . 125
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 380
Center Seat . . . . . . . . . . . . . . . . . . . . . 59
Chains, Tire . . . . . . . . . . . . . . . . . . . . 413
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 134
Charging System Light . . . . . . . . . 149 Check
Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Ignition Transmission Lock . . . 374
Child Restraints Infants and Young Children . . . . . 94
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . 99
Older Children . . . . . . . . . . . . . . . . . . 92
Securing . . . . . . . . . . . . . 111, 114, 115
Systems . . . . . . . . . . . . . . . . . . . . . . . . 96
Circuit Breakers . . . . . . . . . . . . . . . . 381
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 435
Interior Care . . . . . . . . . . . . . . . . . . 441
Climate Control
Systems . . . . . . . . . . . . . . . . . 224, 226
Air Conditioning . . . . . . . . . 224, 226
Dual Automatic . . . . . . . . . . . . . . . 228
Heating . . . . . . . . . . . . . . . . . . 224, 226
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Cluster, Instrument . . . . . . . . . . . . . 138
Collision Damage Repair . . . . . . . 472
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . 124
Compass . . . . . . . . . . . . . . . . . . . . . . . 131
Connections OnStar . . . . . . . . . . . . . . . . . . . . . . . 482 Control
Hill Descent . . . . . . . . . . . . . . . . . . 284
Traction and Electronic
Stability . . . . . . . . . . . . . . . . . . . . . 282
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 153
Control of a Vehicle . . . . . . . . . . . . . 236
Convex Mirrors . . . . . . . . . . . . . . . . . . 47
Coolant
Engine Temperature Gauge . . 144
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 155
Cooling . . . . . . . . . . . . . . .224, 226, 228
Cooling System . . . . . . . . . . . . . . . . . 359
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . . . 471
Cruise Control . . . . . . . . . . . . . . . . . . 285 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Cupholders . . . . . . . . . . . . . . . . . . . . . 124
Customer Assistance . . . . . . . . . . . 468 Offices . . . . . . . . . . . . . . . . . . . . . . . . 467
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 468
Customer Information Service Publications
Ordering Information . . . . . . . . 474
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 465

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
494 Index
D
Damage Repair, Collision . . . . . . . 472
Danger, Warning, and Caution . . . . 3
Data CollectionInfotainment System . . . . . . . . . . 478
OnStar . . . . . . . . . . . . . . . . . . . . . . . 478
Data Recorders, Event . . . . . . . . . 477
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 179
Defensive Driving . . . . . . . . . . . . . . . 236
Diagnostics
OnStar . . . . . . . . . . . . . . . . . . . . . . . 484
Distracted Driving . . . . . . . . . . . . . . . 235
Dome Lamps . . . . . . . . . . . . . . . . . . . 183
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . 158
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Power Locks . . . . . . . . . . . . . . . . . . . . 41
Drive Belt Routing, Engine . . . . . . 464
Driver Assistance Systems . . . . . 288
Driver Information
Center (DIC) . . . . . . . . . . . . . 158, 160
Driving Assistance Systems . . . . . . . . . . 292
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 303
Defensive . . . . . . . . . . . . . . . . . . . . . 236
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 236 Driving (cont'd)
For Better Fuel Economy . . . . . . . 33
Hill and Mountain Roads . . . . . . 245
If the Vehicle is Stuck . . . . . . . . . 247
Loss of Control . . . . . . . . . . . . . . . 238
Off-Road . . . . . . . . . . . . . . . . . . . . . 239
Off-Road Recovery . . . . . . . . . . . 238
Vehicle Load Limits . . . . . . . . . . . 248
Wet Roads . . . . . . . . . . . . . . . . . . . 244
Winter . . . . . . . . . . . . . . . . . . . . . . . . 245
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 228
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 300
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 336
Electrical System Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Fuses and Circuit Breakers . . . 381
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 385, 386
Overload . . . . . . . . . . . . . . . . . . . . . 380
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . 480
Engine Air Cleaner/Filter . . . . . . . . . . . . . 358 Engine (cont'd)
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Compartment Overview . . . . . . . 345
Coolant Heater . . . . . . . . . . . . . . . 260
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 144
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 155
Cooling System . . . . . . . . . . . . . . . 359
Drive Belt Routing . . . . . . . . . . . . 464
Exhaust . . . . . . . . . . . . . . . . . . . . . . 264
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Oil Life System . . . . . . . . . . . . . . . 353
Oil Pressure Gauge . . . . . . . . . . 143
Oil Pressure Light . . . . . . . . . . . . 156
Overheated Protection Operating Mode . . . . . . . . . . . . . 364
Overheating . . . . . . . . . . . . . . . . . . 363
Power Messages . . . . . . . . . . . . . 164
Running While Parked . . . . . . . . 265
Starting . . . . . . . . . . . . . . . . . . . . . . . 258
Entry Lighting . . . . . . . . . . . . . . . . . . . 184
Equipment, Towing . . . . . . . . . . . . . 325
Event Data Recorders . . . . . . . . . . 477
Exit Lighting . . . . . . . . . . . . . . . . . . . . 184
Extender, Seat Belt . . . . . . . . . . . . . . 75
Exterior Lamp Controls . . . . . . . . . 176

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
496 Index
General Information (cont'd)Vehicle Care . . . . . . . . . . . . . . . . . . 342
Glove Box . . . . . . . . . . . . . . . . . . . . . . 124
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . 469
H
Halogen Bulbs . . . . . . . . . . . . . . . . . . 378
Hazard Warning Flashers . . . . . . . 180
Head Restraints . . . . . . . . . . . . . . . . . 58
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 377
Automatic . . . . . . . . . . . . . . . . . . . . . 179
Bulb Replacement . . . . . . . . . . . . 378
Daytime RunningLamps (DRL) . . . . . . . . . . . . . . . . 179
Flash-to-Pass . . . . . . . . . . . . . . . . . 179
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . 378
High-Beam On Light . . . . . . . . . . 157
High/Low Beam Changer . . . . . 179
Lamps On Reminder . . . . . . . . . 157
Heated Steering Wheel . . . . . . . . . . . . . . . 130
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Heated Mirrors . . . . . . . . . . . . . . . . . . . 50 Heater
Engine Coolant . . . . . . . . . . . . . . . 260
Heating . . . . . . . . . . . . . . .224, 226, 228
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . 380
High-Beam On Light . . . . . . . . . . . . 157
High-Speed Operation . . . . . . . . . . 399
Hill and Mountain Roads . . . . . . . . 245
Hill Descent Control (HDC) . . . . . 284
Hill Descent Control Light . . . . . . . 153
Hill Start Assist (HSA) . . . . . . . . . . 282
Home Page . . . . . . . . . . . . . . . . . . . . . 189
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 70
HVAC . . . . . . . . . . . . . . . . .224, 226, 228
I
Idle System Fast . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Ignition Positions . . . . . . . . . . . . . . . 256
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 374
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 46
Indicator Vehicle Ahead . . . . . . . . . . . . . . . . 154 Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . 94
Infotainment . . . . . . . . . . . . . . . . . . . . 186
Infotainment System . . . . . . . . . . . . 478
Instrument Cluster . . . . . . . . . . . . . . 138
Instrument Panel Storage Area . . . . . . . . . . . . . . . . . 124
Interior Rearview Mirrors . . . . . . . . . 51
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jack Auxiliary . . . . . . . . . . . . . . . . . . . . . . 203
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . 426
K
Keyless EntryRemote (RKE) System . . . . . . . . . 37
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
L
Labeling, Tire Sidewall . . . . . . . . . . 391
Lamps Auxiliary RoofMounted Lamp . . . . . . . . . . . . . . 182
Cargo . . . . . . . . . . . . . . . . . . . . . . . . . 183
Daytime Running (DRL) . . . . . . 179
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 183

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 497
Lamps (cont'd)Exterior Controls . . . . . . . . . . . . . . 176
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . 178
Exterior Lighting Battery Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Malfunction Indicator (Check Engine) . . . . . . . . . . . . . 150
On Reminder . . . . . . . . . . . . . . . . . 157
Reading . . . . . . . . . . . . . . . . . . . . . . 183
Lane Departure Warning (LDW) . . . . . . . . . . . . . . . . 295
Lane Departure Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Lane Keep Assist (LKA) . . . . . . . . 297
Lane Keep Assist Light . . . . . . . . . 154
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 75
Lap-Shoulder Belt . . . . . . . . . . . . . . . 71
LATCH System Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . . 111
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . 99
LED Lighting . . . . . . . . . . . . . . . . . . . . 378
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . 184
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Illumination Control . . . . . . . . . . . 182 Lighting (cont'd)
LED . . . . . . . . . . . . . . . . . . . . . . . . . . 378
Lights Airbag On-Off . . . . . . . . . . . . . . . . . 147
Airbag Readiness . . . . . . . . . . . . . 147
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 152
Brake System Warning . . . . . . . 152
Charging System . . . . . . . . . . . . . 149
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . 150
Cruise Control . . . . . . . . . . . . . . . . 158
Door Ajar . . . . . . . . . . . . . . . . . . . . . 158
Engine Coolant Temperature Warning . . . . . . . 155
Engine Oil Pressure . . . . . . . . . . 156
Flash-to-Pass . . . . . . . . . . . . . . . . . 179
Four-Wheel-Drive . . . . . . . . . . . . . 153
Front Fog Lamp . . . . . . . . . . . . . . 157
High-Beam On . . . . . . . . . . . . . . . . 157
High/Low Beam Changer . . . . . 179
Hill Descent Control . . . . . . . . . . 153
Lane Departure Warning . . . . . . 153
Lane Keep Assist . . . . . . . . . . . . . 154
Low Fuel Warning . . . . . . . . . . . . 156
Seat Belt Reminders . . . . . . . . . . 146
Security . . . . . . . . . . . . . . . . . . . . . . 157
StabiliTrak OFF . . . . . . . . . . . . . . . 154 Lights (cont'd)
Tire Pressure . . . . . . . . . . . . . . . . . 156
Tow/Haul Mode . . . . . . . . . . . . . . . 153
Traction Control System
(TCS)/StabiliTrak . . . . . . . . . . . . 155
Traction Off . . . . . . . . . . . . . . . . . . . 154
Locking Rear Axle . . . . . . . . . . . . . . 285
Locks Automatic Door . . . . . . . . . . . . . . . . . 41
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Lockout Protection . . . . . . . . . . . . . . 42
Power Door . . . . . . . . . . . . . . . . . . . . . 41
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Loss of Control . . . . . . . . . . . . . . . . . 238
Low Fuel Warning Light . . . . . . . . . 156
Low-Profile Tires . . . . . . . . . . . . . . . . 390
Lower Anchors and Tethers for Children (LATCH
System) . . . . . . . . . . . . . . . . . . . . . . . . 99
Lumbar Adjustment . . . . . . . . . . . . . . 60 Front Seats . . . . . . . . . . . . . . . . . . . . . 60
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . 459
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . 453
Maintenance Schedule . . . . . . . . . 448