Page 377 of 494

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.
Page 378 of 494
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
Page 379 of 494

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
Page 380 of 494
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.
Page 381 of 494
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
380 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 Accessory power outlet 3 Fuses Usage
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/ SEO battery 1
27 Obstacle detection/ USB ports
28 Body control module 2
32 SEO battery 2
35 AC inverter
36 Amplifier
37 –
Page 382 of 494
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 381
FusesUsage
39 Rear sliding window
42 Right door window motor
43 Front blower
44 SEO
45 Body control module 6
46 Body control module 7
47 Passenger seat
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.
Page 383 of 494
GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
382 Vehicle Care
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Number Usage
1 Accessory power outlet 2 Number Usage
2 SEO/Retained accessory power
3 Universal garage door opener/Interior
rearview mirror
6 Body control module 3
7 Body control module 5
8 Driver window switch/ Mirror switch
9 –
10 Accessory power outlet/Retained
accessory power
11 Accessory power outlet battery
12 Accessory power outlet 1/Cigarette
lighter
13 Discrete logic ignition switch
14 Switch backlighting
17 Body control module 1
19 –
Page 384 of 494

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 5/3/16
Vehicle Care 383
Number Usage20 –
22 HVAC/Auxiliary HVAC/Ignition
23 Instrument cluster/ Ignition sensing
diagnostic module/
Ignition
24 –
25 Data link connector/ Driver seat module
26 Passive entry/Passive start/HVAC
27 –
28 –
29 Park enable/ Electrically adjustable
pedals
30 SEO
31 Accessory/Run/Crank
32 Heated steering wheel
33 –
34 Instrument cluster
36 – Number Usage
37 –
38 4WD TREC
40 Left doors
41 Driver power seat
43 Left heated, cooled or ventilated seats (if
equipped)
44 Right heated, cooled or ventilated seats (if
equipped)
45 –
49 Retained accessory power
50 Run/CrankWheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0250.
(Continued)