
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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294 Driving and Operating
display green. Vehicles may not be
detected on curves, highway exit
ramps, or hills, due to poor visibility;
or if a vehicle ahead is partially
blocked by pedestrians or other
objects. FCA will not detect another
vehicle ahead until it is completely
in the driving lane.
{Warning
FCA does not provide a warning
to help avoid a crash, unless it
detects a vehicle. FCA may not
detect a vehicle ahead if the FCA
sensor is blocked by dirt, snow,
or ice, or if the windshield is
damaged. It may also not detect a
vehicle on winding or hilly roads,
or in conditions that can limit
visibility such as fog, rain,
or snow, or if the headlamps or
windshield are not cleaned or in
proper condition. Keep the
windshield, headlamps, and FCA
sensors clean and in good repair.Collision Alert
When your vehicle approaches
another detected vehicle too rapidly,
the red FCA display will flash on the
windshield. Also, eight rapid
high-pitched beeps will sound from
the front, or both sides of the Safety
Alert Seat will pulse five times.
When this Collision Alert occurs, the
brake system may prepare for driver
braking to occur more rapidly which
can cause a brief, mild deceleration.
Continue to apply the brake pedal
as needed. Cruise control may be
disengaged when the Collision Alert
occurs. Tailgating Alert
The vehicle ahead indicator will
display amber when you are
following a vehicle ahead much too
closely.
Selecting the Alert Timing
The FCA control is on the steering
wheel. Press
[to set the FCA
timing to Far, Medium, Near, or Off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Driving and Operating 297
marking without using a turn signal
in that direction. LDW uses a
camera sensor to detect the lane
markings at speeds of 56 km/h
(35 mph) or greater.
{Warning
The LDW system does not steer
the vehicle. The LDW system
may not:. Provide enough time to
avoid a crash.
. Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or
headlamps are blocked by
dirt, snow, or ice; if they are
not in proper condition; or if
the sun shines directly into
the camera.
. Detect road edges.
. Detect lanes on winding or
hilly roads.
(Continued)
Warning (Continued)
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions.
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@on
the center stack. The control
indicator will light when LDW is on.
When LDW is on,@is green if
LDW is available to warn of a lane
departure. If the vehicle crosses a
detected lane marking without using
the turn signal in that direction,
@
changes to amber and flashes.
Additionally, there will be three
beeps, or the driver seat will pulse
three times on the right or left,
depending on the lane departure
direction.
When the System Does Not
Seem to Work Properly
The system may not detect lanes as
well when there are:
. Close vehicles ahead.
. Sudden lighting changes, such
as when driving through tunnels.
. Banked roads.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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298 Driving and Operating
If the LDW system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
LDW alerts may occur due to tar
marks, shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LDW off if these
conditions continue.
Lane Keep Assist (LKA)
(1500 Series)
If equipped, LKA may help avoid
crashes due to unintentional lane
departures. It may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane
marking without using a turn signal
in that direction. It may also provide
a Lane Departure Warning (LDW)
system alert as the lane marking is
crossed. The LKA system will not
assist or provide an LDW alert if it
detects that you are actively
steering. Override LKA by turning
the steering wheel. LKA uses acamera to detect lane markings
between 60 km/h (37 mph) and
180 km/h (112 mph).
{Warning
The LKA system does not
continuously steer the vehicle.
It may not keep the vehicle in the
lane or give a Lane Departure
Warning (LDW) alert, even if a
lane marking is detected.
The LKA and LDW systems
may not:
. Provide an alert or enough
steering assist to avoid a
lane departure or crash.
. Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or
headlamps are blocked by
dirt, snow, or ice, if they are
not in proper condition, or if
the sun shines directly into
the camera.
. Detect road edges.
(Continued)
Warning (Continued)
.Detect lanes on winding or
hilly roads.
If LKA only detects lane markings
on one side of the road, it will
only assist or provide an LDW
alert when approaching the lane
on the side where it has detected
a lane marking. Even with LKA
and LDW, you must steer the
vehicle. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LKA in
bad weather conditions.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Driving and Operating 327
Use only a round, seven-wire
connector with flat blade terminals
meeting SAE J2863 specifications
for proper electrical connectivity.
For vehicles not equipped with
heavy-duty trailering, the harness is
secured to the vehicle's frame
behind the spare tire mount. The
harness requires the installation of a
trailer connector, which is available
through your dealer.
Heavy-Duty Trailer Wiring Harness
Package
For vehicles equipped with
heavy-duty trailering, the harness
connector is mounted in the bumper.
For vehicles with the fifth wheel/
gooseneck trailer package, the
harness connector is mounted on
the inside of the pickup bed behind
the rear wheel.
The seven-wire harness contains
the following trailer circuits:
.Green/Violet: Right Stop/Turn
Signal
. Yellow/Gray: Left Stop/Turn
Signal
. Gray/Brown: Taillamps/Parking
Lamps
. White: Ground
. White/Green: Back-up Lamps .
Red/Green: Battery Feed
. Dark Blue: Trailer Brake
To help charge a remote
(non-vehicle) battery, press the Tow/
Haul Mode button at the end of the
shift lever. If the trailer is too light for
Tow/Haul Mode, turn on the
headlamps to help charge the
battery.
Camper/Fifth-Wheel Trailer Wiring
Package
For vehicles without the fifth wheel/
gooseneck tralier package,
seven-wire camper harness is under
the rear bumper, attached to the
frame near the rear crossmember.
A connector must be added to the
wiring harness that connects to the
camper.
The harness contains the following
camper/trailer circuits:
. Green/Violet: Right Stop/Turn
Signal
. Yellow/Gray: Left Stop/Turn
Signal
. Gray/Brown: Taillamps/Parking
Lamps

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 339
Vehicle Care
General Information
General Information . . . . . . . . . . 340
California Proposition65 Warning . . . . . . . . . . . . . . . . . 340
California Perchlorate Materials Requirements . . . . . 341
Accessories and Modifications . . . . . . . . . . . . . . . . 341
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 342
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 342
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 343
Engine Oil . . . . . . . . . . . . . . . . . . . . 348
Engine Oil Life System . . . . . . . 351
Automatic Transmission Fluid (6 Speed Transmission) . . . . . 352
Automatic Transmission Fluid (8 Speed Transmission) . . . . . 354
Engine Air Cleaner/Filter . . . . . . 355
Cooling System . . . . . . . . . . . . . . 356
Engine Coolant . . . . . . . . . . . . . . . 357
Engine Overheating . . . . . . . . . . 360
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 362
Engine Fan . . . . . . . . . . . . . . . . . . . 362 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 363
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 363
Washer Fluid . . . . . . . . . . . . . . . . . 363
Brakes . . . . . . . . . . . . . . . . . . . . . . . 364
Brake Fluid . . . . . . . . . . . . . . . . . . . 365
Battery - North America . . . . . . 366
Four-Wheel Drive . . . . . . . . . . . . . 367
Front Axle . . . . . . . . . . . . . . . . . . . . 368
Rear Axle . . . . . . . . . . . . . . . . . . . . 368
Noise Control System . . . . . . . . 370
Starter Switch Check . . . . . . . . . 371
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 371
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 371
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 371
Wiper Blade Replacement . . . . 372
Glass Replacement . . . . . . . . . . 372
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 373
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 373
Halogen Bulbs . . . . . . . . . . . . . . . . 373
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . 373 LED Lighting . . . . . . . . . . . . . . . . . 373
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 374
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 375
Replacement Bulbs . . . . . . . . . . . 375
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . . . 376
Electrical System Overload . . . 376
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 376
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 376
Instrument Panel Fuse Block
(Right) . . . . . . . . . . . . . . . . . . . . . . 379
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 381
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 383
All-Season Tires . . . . . . . . . . . . . . 384
Winter Tires . . . . . . . . . . . . . . . . . . 384
Low-Profile Tires . . . . . . . . . . . . . 385
All-Terrain Tires . . . . . . . . . . . . . . . 385
Tire Sidewall Labeling . . . . . . . . 385
Tire Designations . . . . . . . . . . . . . 388
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 389

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 373
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, contact your dealer.
For any bulb-changing procedure
not listed in this section, contact
your dealer.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge
(HID) lighting system operates at
a very high voltage. If you try to(Continued)
Warning (Continued)
service any of the system
components, you could be
seriously injured. Have your
dealer or a qualified technician
service them.
After an HID headlamp bulb has
been replaced, the beam might be a
slightly different shade than it was
originally. This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
376 Vehicle Care
Electrical System
High Voltage Devices and
Wiring
For an eAssist vehicle, see the
Silverado/Sierra eAssist
supplement.
Electrical System
Overload
The vehicle has fuses to protect
against an electrical system
overload. Fuses also protect power
devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, there
are some spare fuses and a fuse
puller in the Instrument Panel Fuse
Block. The same amperage fuse
can also be borrowed. Choose
some feature of the vehicle that is
not needed to use and replace it as
soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop until the motor cools
and will then restart.
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.
Always clear ice and heavy snow
from the windshield before using the
windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses
The wiring circuits in the vehicle are
protected from short circuits by
fuses. This greatly reduces the
chance of fires caused by electrical
problems.
Look at the silver-colored band
inside the fuse. If the band is broken
or melted, replace the fuse. Be sure
you replace a bad fuse with a new
one of the identical size and rating.
Fuses of the same amperage can
be temporarily borrowed from
another fuse location, if a fuse goes
out. Replace the fuse as soon as
you can.
Engine Compartment
Fuse Block
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
The engine compartment fuse block
is in the engine compartment, on
the driver side of the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
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Vehicle Care 379
FusesUsage
51 Engine control module
52 Interior heater
53 Accessory power module/TPM pump
54 Front washer
55 A/C/Battery regulated voltage
control
56 A/C module/ Battery pack
57 Transmission control module/
Engine control
module
58 Headlamps
74 Electric running boards (if
equipped)
76 Fuel pump prime
Relays Usage
59 Fuel pump
60 Upfitter 2 Relays
Usage
61 Upfitter 3
62 Upfitter 4
63 Trailer parking lamps
64 Run/Crank
65 Upfitter 1
66 Fuel pump 2
67 A/C control
68 Starter
69 Rear window defogger
70 Engine control module
71 Cooling fan clutch
72 CKT 95
73 CKT 92
75 Fuel pump primeInstrument Panel Fuse
Block (Right)
The right instrument panel fuse
block access door is on the
passenger side edge of the
instrument panel.
Pull off the cover to access the fuse
block.