
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
362 Vehicle Care
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before(Continued)
Caution (Continued)
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil 0348.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 377
Lift the cover to access the fuse
block.
Caution
Spilling liquid on any electrical
component on the vehicle may
damage it. Always keep the
covers on any electrical
component.
A fuse puller is available in the left
instrument panel fuse block.
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.
Fuses Usage
1 Trailer brake
2 Trailer battery Fuses
Usage
3 ABS pump

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
378 Vehicle Care
FusesUsage
4 Instrument panel BEC 1
5 MSB passenger
6 4WD transfer case electronic control
7 Electric park brake
8 Instrument panel BEC 2
9 MSB driver
10 Rear window defogger
11 Starter
12 Cooling fan 1
13 Cooling fan 2
14 Left trailer stop/ Turn lamps
15 Trailer parking lamps
16 Trailer reverse lamps
17 Right trailer stop/ Turn lamps
18 Fuel pump Fuses
Usage
19 Integrated chassis control module
20 Electronic suspension control
module
21 Fuel pump power module
22 Upfitter 1
23 Upfitter 2
24 Front wiper
25 ABS Valves
26 Upfitter 2
27 Upfitter 3
28 Right parking lamps
29 Left parking lamps
30 Upfitter 3
31 Upfitter 4
32 Upfitter 4
33 Reverse lamps
34 Engine control module/Ignition Fuses
Usage
35 A/C clutch
36 Heated mirrors
37 Upfitter 1
38 Center high-mounted
stoplamp
39 Miscellaneous/ Ignition
40 Transmission/ Ignition
41 Fuel pump 2
42 Cooling fan clutch
43 Engine
44 Fuel injectors A –odd
45 Fuel injectors B –even
46 O2 Sensor B
47 Throttle control
48 Horn
49 Fog lamps
50 O2 Sensor A

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 387
(8) Temporary Use Only:Only
use a temporary spare tire until
the road tire is repaired and
replaced. This spare tire should
not be driven on over 112 km/h
(70 mph), or 88 km/h (55 mph)
when pulling a trailer, with the
proper inflation pressure. See
Full-Size Spare Tire 0417.
Light Truck (LT-Metric) Tire
(1) Tire Size:The tire size code
is a combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type, and service description. See the
“Tire Size”
illustration later in this
section for more detail.
(2) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
(3) Dual Tire Maximum Load
:
Maximum load that can be
carried and the maximum
pressure needed to support that
load when used in a dual
configuration. For information on
recommended tire pressure see
Tire Pressure 0391 and Vehicle
Load Limits 0250.
(4) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with the U.S. Department of
Transportation Motor Vehicle
Safety Standards.
DOT Tire Date of
Manufacture
:The last four
digits of the TIN indicate the tire
manufactured date. The first two
digits represent the week
(01-52) and the last two digits,
the year. For example, the third
week of the year 2010 would
have a four-digit DOT date
of 0310.
(5) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are the
Tire Identification Number (TIN).
The TIN shows the
manufacturer and plant code,
tire size, and date the tire was
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(6) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 417
To store the jack and jack tools:
1. Wing Nut Retaining WheelBlocks
2. Wheel Blocks
3. Wing Nut Retaining Tool Kit
4. Wheel Wrench and Extensions
5. Tool Bag
6. Jack Mounting Bracket
7. Jack
8. Bolt Retaining Wheel Blocks
1. Put the tools (4) in the tool bag (5) and place them in the
retaining bracket (3).
2. Tighten down the wing nut (3). 3. Assemble the wheel blocks (2)
and jack (7) together with the
wing nut (1) and retaining
bolt (8).
4. Position the jack (7) in the mounting bracket (6). Position
the holes in the base of the
jack (7) onto the pin in the
mounting bracket (6).
5. Return them to their original location in the vehicle. See
“Removing the Spare Tire and
Tools.”
Full-Size Spare Tire
If this vehicle came with a full-size
spare tire, it was fully inflated when
new, however, it can lose air over
time. Check the inflation pressure
regularly. See Tire Pressure0391
and Vehicle Load Limits 0250. For
instructions on how to remove,
install, or store a spare tire, see Tire
Changing 0408.
If equipped with a temporary use
full-size spare tire, it is indicated on
the tire sidewall. See Tire Sidewall
Labeling 0385. This spare tire
should not be driven on over 112 km/h (70 mph), or 88 km/h
(55 mph) when pulling a trailer, at
the proper inflation pressure. Repair
and replace the road tire as soon as
it is convenient, and stow the spare
tire for future use.
Caution
If the vehicle has four-wheel drive
and a different size spare tire is
installed, do not drive in
four-wheel drive until the flat tire
is repaired and/or replaced. The
vehicle could be damaged and
the repairs would not be covered
by the warranty. Never use
four-wheel drive when a different
size spare tire is installed on the
vehicle.
The vehicle may have a different
size spare tire than the road tires
originally installed on the vehicle.
This spare tire was developed for
use on this vehicle, so it is all right
to drive on it. If the vehicle has

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 423
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of
recreational vehicle towing are
dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly
towing is towing the vehicle with two
wheels on the ground and two
wheels on a dolly.
Follow the tow vehicle
manufacturer’s instructions. See
your dealer or trailering professional
for additional advice and equipment
recommendations.
Caution
Use of a shield mounted in front
of the vehicle grille could restrict
airflow and cause damage to the
transmission. The repairs would
not be covered by the vehicle
(Continued)
Caution (Continued)
warranty. If using a shield, only
use one that attaches to the
towing vehicle.
Dinghy Towing
Two-Wheel-Drive Vehicles
Caution
If the two-wheel-drive vehicle is
towed with all four wheels on the
ground, the drivetrain(Continued)
Caution (Continued)
components could be damaged.
The repairs would not be covered
by the vehicle warranty.
Two-wheel-drive vehicles should not
be towed with all four wheels on the
ground.
Four-Wheel-Drive Vehicles
Only dinghy tow four-wheel-drive
vehicles with a two-speed transfer
case that have an N (Neutral) and a
Four-Wheel Drive Low (4 (
n) setting.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
438 Service and Maintenance
keep the vehicle in good working
condition, improves fuel economy,
and reduces vehicle emissions.
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more
frequent checks and services.
Normal Service
All maintenance services, including
those listed under Additional
Required Services, are for
vehicles that:
.Carry passengers and cargo
within recommended limits on
the Tire and Loading Information
label. See Vehicle Load
Limits 0250.
. Are driven on reasonable road
surfaces within legal driving
limits.
. Use the recommended fuel. See
Fuel 0300. Severe Service
In addition to the normal service
schedule, some vehicles require
service more often. Severe service
is for vehicles that are:
.
Mainly driven in heavy city traffic
in hot weather.
. Mainly driven in hilly or
mountainous terrain.
. Frequently towing a trailer.
. Used for high-speed or
competitive driving.
. Used for taxi, police, or delivery
service.
{Warning
Performing maintenance work can
be dangerous and can cause
serious injury. Perform
maintenance work only if the
required information, proper tools,
and equipment are available.
If they are not, see your dealer to
have a trained technician do the
work. See Doing Your Own
Service Work 0342.
Maintenance
Schedule
Owner Checks and Services
At Each Fuel Stop
.
Check the engine oil level. See
Engine Oil 0348.
Once a Month
. Check the tire inflation
pressures. See Tire
Pressure 0391.
. Inspect the tires for wear. See
Tire Inspection 0397.
. Check the windshield washer
fluid level. See Washer
Fluid 0363.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km/600 mi. If driven
under the best conditions, the
engine oil life system may not
indicate the need for vehicle service
for up to a year. The engine oil and
filter must be changed at least once