2018 GMC SIERRA air condition

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 383
FusesUsage
3 Antilock brake system pump
4 Instrument panel BEC 1
5 Passenger motorized seat belt
6 4WD transfer case electronic control
7 Electric park brake
8 Instrument panel BEC 2
9 Driver motorized seat belt
10 Rear window defogger
11 Starter
12 Cooling fan 1
13 Cooling fan 2
14 Left trailer stop/ Turn signal lamps
15 Trailer parking lamps Fuses
Usage
16 Trailer reverse lamps
17 Right trailer stop/ Turn signal lamps
18 Fuel pump
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 Antilock brake system valve
26 Upfitter 2
27 Upfitter 3
28 Right parking lamps
29 Left parking lamps Fuses
Usage
30 Upfitter 3
31 Upfitter 4
32 Upfitter 4
33 Reverse lamps
34 Engine control module/Ignition
35 Air conditioning 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
384 Vehicle Care
FusesUsage
45 Fuel injectors B–even
46 O2 Sensor B
47 Throttle control
48 Horn
49 Fog lamps
50 O2 Sensor A
51 Engine control module
52 Interior heater
53 Accessory power module/TPM pump
54 Front washer
55 Air conditioning/ Battery regulated
voltage control
56 Air conditioning module/
Battery pack
57 Transmission control module/
Engine control
module Fuses
Usage
58 Headlamps
74 Electric running boards (if
equipped)
76 Fuel pump prime / MGU motor
77 Cabin pump motor
79 Vacuum pump
Relays Usage
59 Fuel pump
60 Upfitter 2
61 Upfitter 3
62 Upfitter 4
63 Trailer parking lamps
64 Run/Crank
65 Upfitter 1
66 Fuel pump 2
67 Air conditioning control
68 Starter Relays
Usage
69 Rear window defogger
70 Engine control module
71 Vacuum pump/ Cooling fan clutch
72 CKT 95
73 CKT 92
75 Fuel pump prime/ MGU motor
78 Vacuum pump switch

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
Vehicle Care 395
would mean that the tire's
sidewall is 75 percent as high as
it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Load Range
:Load Range.
(7) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch of
the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials. Bead
:The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire
:A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread.
Cold Tire Pressure
:The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire Pressure
0 397.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 399
inflation pressure is high, press
on the metal stem in the center
of the tire valve to release air.
Re-check the tire pressure with
the tire gauge.
Put the valve caps back on the
valve stems to keep out dirt and
moisture and prevent leaks. Use
only valve caps designed for the
vehicle by GM. TPMS sensors
could be damaged and would
not be covered by the vehicle
warranty.
Tire Pressure for
High-Speed Operation
{Warning
Driving at high speeds, 160 km/h
(100 mph) or higher, puts
additional strain on tires.
Sustained high-speed driving
causes excessive heat buildup
and can cause sudden tire failure.(Continued)
Warning (Continued)
This could cause a crash, and
you or others could be killed.
Some high-speed rated tires
require inflation pressure
adjustment for high-speed
operation. When speed limits and
road conditions allow the vehicle
to be driven at high speeds, make
sure the tires are rated for
high-speed operation, are in
excellent condition, and are set to
the correct cold tire inflation
pressure for the vehicle load.
Vehicles with P275/55R20 or
P285/50R20 size tires require
inflation pressure adjustment when
driving the vehicle at speeds of
160 km/h (100 mph) or higher. Set
the cold tire inflation pressure to
20 kPa (3 psi) above the
recommended cold tire pressure
shown on the Tire and Loading
Information label. Return the tires to the
recommended cold tire inflation
pressure when high-speed driving
has ended. See
Vehicle Load Limits
0 248 andTire Pressure 0397.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor
the air pressure in your tires and
transmit tire pressure readings to a
receiver located in the vehicle.
Each tire, including the spare (if
provided), should be checked
monthly when cold and inflated to
the inflation pressure recommended
by the vehicle manufacturer on the
vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or
tire inflation pressure label, you
should determine the proper tire
inflation pressure for those tires.)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
400 Vehicle Care
As an added safety feature, your
vehicle has been equipped with a
tire pressure monitoring system
(TPMS) that illuminates a low tire
pressure telltale when one or more
of your tires is significantly
under-inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
soon as possible, and inflate them
to the proper pressure. Driving on a
significantly under-inflated tire
causes the tire to overheat and can
lead to tire failure. Under-inflation
also reduces fuel efficiency and tire
tread life, and may affect the
vehicle's handling and stopping
ability.
Please note that the TPMS is not a
substitute for proper tire
maintenance, and it is the driver's
responsibility to maintain correct tire
pressure, even if under-inflation has
not reached the level to trigger
illumination of the TPMS low tire
pressure telltale.Your vehicle has also been
equipped with a TPMS malfunction
indicator to indicate when the
system is not operating properly.
The TPMS malfunction indicator is
combined with the low tire pressure
telltale. When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated.
This sequence will continue upon
subsequent vehicle start-ups as
long as the malfunction exists.
When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent
the TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.See
Tire Pressure Monitor
Operation 0400.
See Radio Frequency Statement
0 475.
Tire Pressure Monitor
Operation
This vehicle may have a Tire
Pressure Monitor System (TPMS).
The TPMS is designed to warn the
driver when a low tire pressure
condition exists. TPMS sensors are
mounted onto each tire and wheel
assembly, excluding the spare tire
and wheel assembly. The TPMS
sensors monitor the air pressure in
the tires and transmit the tire
pressure readings to a receiver
located in the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 401
When a low tire pressure condition
is detected, the TPMS illuminates
the low tire pressure warning light
located on the instrument cluster.
If the warning light comes on, stop
as soon as possible and inflate the
tires to the recommended pressure
shown on the Tire and Loading
Information label. SeeVehicle Load
Limits 0248.
A message to check the pressure in
a specific tire displays in the Driver
Information Center (DIC). The low
tire pressure warning light and the
DIC warning message come on at
each ignition cycle until the tires are
inflated to the correct inflation
pressure. If the vehicle has DIC
buttons, tire pressure levels can be
viewed. For additional information
and details about the DIC operation
and displays, see Driver Information
Center (DIC) (Uplevel and Denali
Cluster) 0160 orDriver Information
Center (DIC) (Base Level Cluster)
0 158.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then turn off as the vehicle is driven. This
could be an early indicator that the
air pressure is getting low and
needs to be inflated to the proper
pressure.
A Tire and Loading Information label
shows the size of the original
equipment tires and the correct
inflation pressure for the tires when
they are cold. See
Vehicle Load
Limits 0248, for an example of the
Tire and Loading Information label
and its location. Also see Tire
Pressure 0397.
The TPMS can warn about a low
tire pressure condition but it does
not replace normal tire
maintenance. See Tire Inspection
0 404, Tire Rotation 0405 andTires
0 389.
Caution
Tire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
(Continued)
Caution (Continued)
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.
TPMS Malfunction Light and
Message
The TPMS will not function properly
if one or more of the TPMS sensors
are missing or inoperable. When the
system detects a malfunction, the
low tire pressure warning light
flashes for about one minute and
then stays on for the remainder of
the ignition cycle. A DIC warning
message also displays. The
malfunction light and DIC warning
message come on at each ignition
cycle until the problem is corrected.
Some of the conditions that can
cause these to come on are:
.One of the road tires has been
replaced with the spare tire. The
spare tire does not have a