power steering GMC SIERRA 2018 Owner's Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 365
Caution (Continued)
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil 0350.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing, and/or high
outside temperatures, the fan speed
increases as the clutch more fully
engages, so an increase in fan
noise may be heard. This is normal
and should not be mistaken as the
transmission slipping or making
extra shifts. It is merely the cooling
system functioning properly. The fan will slow down when additional
cooling is not required and the
clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fan(s), the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Power Steering Fluid
(1500 Series)
The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
See
Engine Compartment Overview
0 345 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
366 Vehicle Care
Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid
To check the power steering fluid:1. Turn the ignition off and let the engine compartment
cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the
dipstick.
The level should be between the
ADD and FULL marks. If necessary,
add only enough fluid to bring the
level up to the hashed area between
the ADD and FULL marks.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants 0456. Always use the
proper fluid.
Caution
Use of the incorrect fluid may
damage the vehicle and the
damages may not be covered by
the vehicle warranty. Always use
the correct fluid listed in
Recommended Fluids and
Lubricants 0456.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes on
when the washer fluid is low. The
message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview 0345 for
reservoir location.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
386 Vehicle Care
FusesUsage
2 Accessory power outlet 4
7 Body control module 4
8 Body control module 8
9 Rear seat entertainment
10 Cargo lamp
15 Steering wheel controls
18 Radio
19 –
20 Sunroof
23 Airbag/Info
26 Export/Power take off/ Special equipment
option/Battery 1
27 Obstacle detection/ USB ports
28 Body control module 2
32 Special equipment option/Battery 2 Fuses
Usage
35 Air conditioning inverter
36 Amplifier
37 Battery system
39 Rear sliding window
42 Right door window motor
43 Front blower
44 Special equipment option
45 Body control module 6
46 Body control module 7
47 Passenger seat
Relays Usage
50 Retained accessory power
51 Rear sliding window open
52 Rear sliding window closeInstrument Panel Fuse
Block (Left)
The left instrument panel fuse block
access door is on the driver side
edge of the instrument panel.
Pull off the cover to access the fuse
block.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
388 Vehicle Care
FusesUsage
19 –
20 –
22 Heating, ventilation, and air conditioning/
Auxiliary heating,
ventilation, and air
conditioning/Ignition
23 Instrument cluster/ Ignition sensing
diagnostic module/
Ignition
24 –
25 Data link connector/ Driver seat module
26 Passive entry/Passive start/Heating,
ventilation, and air
conditioning
27 – Fuses
Usage
28 –
29 Park enable/ Electrically adjustable
pedals
30 Special equipment option
31 Accessory/Run/Crank
32 Heated steering wheel
33 –
34 Instrument cluster
36 –
37 –
38 4WD transfer case electronic control
40 Left doors
41 Driver power seat Fuses
Usage
43 Left heated, cooled or ventilated seats (if
equipped)
44 Right heated, cooled or ventilated seats (if
equipped)
45 –
Relays Usage
49 Retained accessory power
50 Run/Crank

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
440 Vehicle Care
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
1500 Series vehicles, at least every
other oil change lubricate the outer
tie rod ends.
2500/3500 Series vehicles, at least
every other engine oil change
lubricate the upper and lower
control arm ball joints. Control arm
ball joints on 1500 series vehicles
are maintenance-free.
2500/3500 Series vehicles equipped
with steering linkage, at least every
other engine oil change lubricate the
tie rod ball joints, idler arm pivot
shaft bearings, idler arm socket, and
pitman arm socket.
Caution
Lubrication of applicable steering/
suspension points should not be
done unless the temperature is
−12 °C (10 °F) or higher,
or damage could result.
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any
corrosive materials from the
underbody. Take care to thoroughly
clean any areas where mud and other debris can collect. If equipped
with power assist steps, extend
them and then use a high pressure
wash to clean all joints and gaps.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water
can overcome the seals and
contaminate the fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and
should be replaced.
Sheet Metal Damage
If the vehicle is damaged and
requires sheet metal repair or
replacement, make sure the body
repair shop applies anti-corrosion
material to parts repaired or
replaced to restore corrosion
protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Service and Maintenance 457
UsageFluid/Lubricant
Front Axle –Four-Wheel Drive SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in
Canada 89021678).
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 19353126, in Canada 19299819).
Hydraulic Power Steering System (2500/3500 Series Only) GM Power Steering Fluid (GM Part No. 19329450, in Canada 19329451).
Key Lock Cylinders, Hood Hinges, Body Door Hinge Pins, Tailgate
Hinge and Linkage, Fuel Door Hinge,
Tailgate Handle Pivot Points, Hinges, Latch Bolt, and Linkage Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Rear Axle (1500 Series) SAE 75W-85 Synthetic Axle Lubricant (GM Part No. 19300457, in Canada 19300458).
Rear Axle (2500/3500 Series) SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88900401, in Canada 89021678).
Transfer Case (Four-Wheel Drive) DEXRON-VI Automatic Transmission Fluid.
Weatherstrip Conditioning Weatherstrip Lubricant (GM Part No. 3634770, in Canada 10953518) or Dielectric Silicone Grease (GM Part No. 12345579, in Canada 10953481).
Weatherstrip Squeaks Synthetic Grease with Teflon, Superlube (GM Part No. 12371287, in Canada 10953437).
Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 495
Exterior Lamps Off Reminder . . . 178
Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . 185
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 365
Fast Idle System . . . . . . . . . . . . . . . . 259
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . . 13
Filter, Engine Air Cleaner . . . . . . . . . . . 358
Fixed Mast Antenna . . . . . . . . . . . . 194
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 179
Flashers, Hazard Warning . . . . . . 180
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 413 Changing . . . . . . . . . . . . . . . . . . . . . 415
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Floor Console Storage . . . . . . . . . . 126
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 444
Fluid AutomaticTransmission . . . . . . . . . . . 354, 357
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 368
Four-Wheel Drive Transfer Case . . . . . . . . . . . . . . . 272
Power Steering . . . . . . . . . . . . . . . 365 Fluid (cont'd)
Washer . . . . . . . . . . . . . . . . . . . . . . . 366
Fog Lamps . . . . . . . . . . . . . . . . . . . . . 181
Folding Mirrors . . . . . . . . . . . . . . . . . . 49
Forward Automatic Braking . . . . . 294
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . 292
Four-Wheel Drive . . . . . . . . . . 272, 370
Four-Wheel-Drive Light . . . . . . . . . 153
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . 475
Front Axle . . . . . . . . . . . . . . . . . . . . . . 370
Front Fog Lamp Light . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . 59
Heated and Ventilated . . . . . . . . . . 65
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Additives . . . . . . . . . . . . . . . . . . . . . 300
Economy Driving . . . . . . . . . . . . . . . 33
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 303
Filling the Tank . . . . . . . . . . . . . . . 301
Foreign Countries . . . . . . . . . . . . 300
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 142
Low Fuel Warning Light . . . . . . . 156
Management, Active . . . . . . . . . . 264
Requirements, California . . . . . 300 Full-Size Spare Tire . . . . . . . . . . . . 425
Fuses
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 381
Fuses and Circuit Breakers . . . 381
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 385, 386
G
Garage Door Opener . . . . . . . . . . . 172
Programming . . . . . . . . . . . . . . . . . 172
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . 376
Gauges
Engine CoolantTemperature . . . . . . . . . . . . . . . . 144
Engine Oil Pressure . . . . . . . . . . 143
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Odometer . . . . . . . . . . . . . . . . . . . . . 142
Speedometer . . . . . . . . . . . . . . . . . 142
Tachometer . . . . . . . . . . . . . . . . . . . 142
Transmission Temperature . . . . 145
Trip Odometer . . . . . . . . . . . . . . . . 142
Voltmeter . . . . . . . . . . . . . . . . . . . . . 145
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . 137
General Information
Service and Maintenance . . . . . 446
Towing . . . . . . . . . . . . . . . . . . . . . . . . 303

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 499
Parking (cont'd)Over Things That Burn . . . . . . . 264
Parking Assist . . . . . . . . . . . . . . . . . . 289
Parking or Backing Assistance Systems . . . . . . . . . . 289
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . 149
Passenger Compartment Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Passenger Sensing System . . . . . 86
Perchlorate Materials Requirements, California . . . . . . 343
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 165
Phone Apple CarPlay andAndroid Auto . . . . . . . . . . . . . . . . 217
Bluetooth . . . . . . . . . . . . . . . . 211, 213
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . . . . . 340
Port USB . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Power
Door Locks . . . . . . . . . . . . . . . . . . . . . 41
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Outlets . . . . . . . . . . . . . . . . . . . . . . . 133
Protection, Battery . . . . . . . . . . . . 185
Retained Accessory (RAP) . . . 260 Power (cont'd)
Seat Adjustment . . . . . . . . . . . . . . . . 60
Steering Fluid . . . . . . . . . . . . . . . . . 365
Windows . . . . . . . . . . . . . . . . . . . . . . . 52
Power Assist Steps . . . . . . . . . . . . . . 43
Pregnancy, Using Seat Belts . . . . 74
Privacy Vehicle Data Recording . . . . . . . 477
Program
Courtesy Transportation . . . . . . 471
Proposition 65 Warning,
California . . . . . . . . . . . .343, 369, 426, Back Cover
R
Radio Frequency Statement . . . . 475
Radio Reception . . . . . . . . . . . . . . . . 193
Radios
AM-FM Radio . . . . . . . . . . . . . . . . . 190
Satellite . . . . . . . . . . . . . . . . . . . . . . . 192
Reading Lamps . . . . . . . . . . . . . . . . . 183
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . 371 Locking . . . . . . . . . . . . . . . . . . . . . . . 285
Rear Seats . . . . . . . . . . . . . . . . . . 66, 68
Rear Vision Camera (RVC) . . . . . 289
Rear Windows . . . . . . . . . . . . . . . . . . . 54
Rearview Mirrors . . . . . . . . . . . . . . . . 52 Rearview Mirrors (cont'd)
Automatic Dimming . . . . . . . . . . . . . 52
Reclining Seatbacks . . . . . . . . . . . . . 61
Recognition Voice . . . . . . . . . . . . . . . . . . . . . . . . . 205
Recommended Fluids and Lubricants . . . . . . . . . . . . . . . . . . . . . 456
Records Maintenance . . . . . . . . . . . . . . . . . . 459
Recreational Vehicle Towing . . . . 430
Reimbursement Program, GM Mobility . . . . . . . . . . . . . . . . . . . 469
Remote Keyless Entry (RKE) System . . . . . . . . . . . . . . . . . . . . . . . . . 37
Remote Vehicle Start . . . . . . . . . . . . 39
Replacement Parts Airbags . . . . . . . . . . . . . . . . . . . . . . . . . 92
Maintenance . . . . . . . . . . . . . . . . . . 458
Replacing Airbag System . . . . . . . . 92
Replacing LATCH System Parts after a Crash . . . . . . . . . . . . 111
Replacing Seat Belt System Parts after a Crash . . . . . . . . . . . . . 76
Reporting Safety Defects Canadian Government . . . . . . . . 476
General Motors . . . . . . . . . . . . . . . 477
U.S. Government . . . . . . . . . . . . . 476

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 501
StabiliTrakOFF Light . . . . . . . . . . . . . . . . . . . . . 154
Start Assist, Hill . . . . . . . . . . . . . . . . . 282
Start Vehicle, Remote . . . . . . . . . . . 39
Starter Switch Check . . . . . . . . . . . 374
Starting the Engine . . . . . . . . . . . . . 258
Steering . . . . . . . . . . . . . . . . . . . . . . . . 237 Fluid, Power . . . . . . . . . . . . . . . . . . 365
Heated Wheel . . . . . . . . . . . . . . . . 130
Wheel Adjustment . . . . . . . . . . . . 129
Wheel Controls . . . . . . . . . . . . . . . 129
Steps Power Assist . . . . . . . . . . . . . . . . . . . 43
Stoplamps and Back-up Lamps Bulb Replacement . . . . . . . . . . . . 378
Storage Areas
Center Console . . . . . . . . . . . . . . . 125
Floor Console . . . . . . . . . . . . . . . . 126
Glove Box . . . . . . . . . . . . . . . . . . . . 124
Instrument Panel . . . . . . . . . . . . . 124
Sunglasses . . . . . . . . . . . . . . . . . . . 125
Storage Compartments . . . . . . . . . 124
Struts Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
Stuck Vehicle . . . . . . . . . . . . . . . . . . . 247
Sun Visors . . . . . . . . . . . . . . . . . . . . . . . 55
Sunglass Storage . . . . . . . . . . . . . . . 125
Sunroof . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Switches
Airbag On-Off . . . . . . . . . . . . . . . . . . . 84
Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System Forward CollisionAlert (FCA) . . . . . . . . . . . . . . . . . . 292
Infotainment . . . . . . . . . . . . . 186, 478
Noise Control . . . . . . . . . . . . . . . . . 373
Systems Driver Assistance . . . . . . . . . . . . . 288
T
Tachometer . . . . . . . . . . . . . . . . . . . . . 142
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . . 43
TaillampsBulb Replacement . . . . . . . . . . . . 378
Text Telephone (TTY) Users . . . . 468
Theft-Deterrent Systems . . . . . . . . . 46
Immobilizer . . . . . . . . . . . . . . . . . . . . . 46
Throttle, Adjustable . . . . . . . . . . . . . 256
Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 All-Season . . . . . . . . . . . . . . . . . . . . 389
All-Terrain . . . . . . . . . . . . . . . . . . . . 391
Buying New Tires . . . . . . . . . . . . . 408
Chains . . . . . . . . . . . . . . . . . . . . . . . . 413
Changing . . . . . . . . . . . . . . . . . . . . . 415
Designations . . . . . . . . . . . . . . . . . 393 Tires (cont'd)
Different Size . . . . . . . . . . . . . . . . . 409
Full-Size Spare . . . . . . . . . . . . . . . 425
If a Tire Goes Flat . . . . . . . . . . . . 413
Inspection . . . . . . . . . . . . . . . . . . . . 404
Low Profile . . . . . . . . . . . . . . . . . . . 390
Pressure . . . . . . . . . . . . . . . . . 397, 399
Pressure Light . . . . . . . . . . . . . . . . 156
Pressure Monitor Operation . . 400
Pressure Monitor System . . . . . 399
Rotation . . . . . . . . . . . . . . . . . . . . . . 405
Sidewall Labeling . . . . . . . . . . . . . 391
Terminology and Definitions . . 395
Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . . . 410
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . .411
Wheel Replacement . . . . . . . . . . 412
When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 407
Winter . . . . . . . . . . . . . . . . . . . . . . . . 390
Tow/Haul Mode . . . . . . . . . . . . . . . . . 271
Tow/Haul Mode Light . . . . . . . . . . . 153
Towing Driving Characteristics . . . . . . . . 303
Equipment . . . . . . . . . . . . . . . . . . . . 325
General Information . . . . . . . . . . 303
Recreational Vehicle . . . . . . . . . . 430