2018 GMC SIERRA DENALI clock

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 225
9 : Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Turn the
knob all the way counterclockwise
to turn the fan off.
Air Delivery Mode Controls :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets. [ : Air is directed to the floor
outlets, with some air directed to the
windshield, side window, and
second row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The system
automatically forces outside air into
the vehicle. Do not drive the vehicle until all the
windows are clear.
See Air Vents 0 231 .
@ : Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
226 Climate Controls
Climate Control Systems (with Air Conditioning) With this system the heating, cooling, and ventilation can be controlled.
1. Fan Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Defrost
5. TEMP (Temperature Control) 6.
K (Rear Window Defogger, If
Equipped)
f (Outside Heated Mirror, If
Equipped)
8 (Outside Air, If Equipped)
7.
@ Air Recirculation TEMP : Turn clockwise or
counterclockwise to increase or
decrease the temperature inside the
vehicle.
9 : Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Turn the
knob all the way counterclockwise
to turn the fan off.
Air Delivery Mode Controls :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
[ : Air is directed to the floor
outlets, with some air directed to the
windshield and side window outlets.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 229The recirculation light will not come
on when automatically controlled.
Press
@ to manually select
recirculation; press it again to select
outside air.
Do not cover the solar sensor on the
top of the instrument panel near the
windshield. This sensor regulates
air temperature based on sun load.
See “ Sensors ” later in this section.
Manual Operation
O : Press to turn the climate control
system on or off. Outside air still
enters the vehicle, and is directed to
the floor. This direction can be
changed by pressing the air
delivery mode.
9 : Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Press the
knob to turn the fan off.
Press AUTO to return to automatic
operation. Driver and Passenger
Temperature Control : The
temperature can be adjusted
separately for the driver and
passenger.
Turn the knob clockwise or
counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC : Press to link the passenger
temperature setting to the driver
setting. The SYNC indicator light will
turn on. When the passenger setting
is adjusted, the SYNC indicator light
is off.
The driver side or passenger side
temperature display shows the
temperature setting increasing or
decreasing.
Air Delivery Mode Control :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button. Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
Some air is directed toward the
windshield and side window outlets.
[ : Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents. The system
automatically forces outside air into
the vehicle and the air conditioning
compressor will run, unless the
outside temperature is close to
freezing.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The air

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
276 Driving and Operating 2. Turn the knob to 4
n . Wait for
the 4
n indicator light to stop
flashing before shifting the
transmission into gear.
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
n indicator light will flash for
30 seconds and not complete the
shift. After 30 seconds the transfer
case will shift to 4
m . Turn the knob
to 4
m to see the indicator. With the
vehicle moving less than 5 km/h
(3 mph), and the transmission in
N (Neutral), attempt the shift again.
Shifting Out of 4
n1. To shift out of 4
n the vehicle
must be stopped or moving
less than 5 km/h (3 mph) with
the transmission in N (Neutral)
and the ignition in on. It is best
for the vehicle to be moving
1.6 to 3.2 km/h (1 to 2 mph). 2. Turn the knob to 4
m or 2
m .
Wait for the 4
m or 2
m indicator
light to stop flashing before
shifting the transmission
into gear.
If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
m or 2
m indicator light will flash
for 30 seconds, but will not complete
the shift. With the vehicle moving
less than 5 km/h (3 mph), and the
transmission in N (Neutral), attempt
the shift again.
Shifting Into N (Neutral)
To shift:
1. Park the vehicle on a level
surface.
2. Set the parking brake and
press and hold the brake
pedal. See Parking Brake
0 281 .
3. Start the vehicle or turn the
ignition on.
4. Shift the transmission to
N (Neutral). 5. Shift the transfer case to 2
m .
6. Turn the transfer case knob
clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly
release the knob to the 4
n position. The N (Neutral) light
will come on when the transfer
case shift to N (Neutral) is
complete.
7. With the engine running, verify
that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then to D (Drive). There should
be no movement of the vehicle
while shifting the transmission.
8. Turn the engine off, and the
ignition to ACC/ACCESSORY.
9. Place the transmission shift
lever in P (Park). See
Recreational Vehicle Towing
0 430 .
10. Turn the ignition off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 279Shifting Out of 4
nTo shift:
1. The vehicle must be stopped or
moving less than 5 km/h
(3 mph) with the transmission
in N (Neutral) and the ignition
on. It is best for the vehicle to
be moving 1.6 to 3.2 km/h
(1 to 2 mph).
2. Turn the knob to 4
m , AUTO,
or 2
m . Wait for the 4
m , AUTO,
or 2
m indicator light to stop
flashing before shifting the
transmission into gear.
Caution
Shifting the transmission into gear
before the requested mode
indicator light has stopped
flashing could damage the
transfer case. If the transmission is in gear and/or
moving more than 5 km/h (3 mph),
the 4
m , AUTO, or 2
m indicator light
will flash for 30 seconds but will not
complete the shift. With the vehicle
moving less than 5 km/h (3 mph),
and the transmission in N (Neutral),
attempt the shift again.
Shifting Into N (Neutral)
To shift into N (Neutral):
1. Park the vehicle on a level
surface.
2. Set the parking brake and
press and hold the brake
pedal. See Parking Brake
0 281 .
3. Start the vehicle or turn the
ignition on.
4. Shift the transmission to
N (Neutral).
5. Shift the transfer case to 2
m . 6. Turn the transfer case knob
clockwise to N (Neutral) until it
stops and hold it there until the
N (Neutral) light starts blinking.
This will take at least
10 seconds. Then slowly
release the knob to the 4
n position. The N (Neutral) light
will come on when the transfer
case shift to N (Neutral) is
complete.
7. With the engine running, verify
that the transfer case is in
N (Neutral) by shifting the
transmission to R (Reverse),
then shift the transmission to
D (Drive). There should be no
movement of the vehicle while
shifting the transmission.
8. Turn the engine off, and the
ignition to ACC/ACCESSORY.
9. Place the transmission shift
lever in P (Park). See
Recreational Vehicle Towing
0 430 .
10. Turn the ignition to off.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
362 Vehicle Care
{ WarningPlain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
{ WarningSteam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool. WarningFailure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant
is not visible in the surge tank,
contact your dealer.
If no coolant is visible in the surge
tank, add coolant.
Light-Duty
Coolant Surge
Tank
Pressure Cap Heavy-Duty
Coolant Surge
Tank
Pressure Cap
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot. Turn the pressure cap slowly
counterclockwise about one full
turn. If a hiss is heard, wait for
that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap
slowly, and remove it.
3. Fill the coolant surge tank with
the proper mixture to the full
cold mark.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until the
engine coolant temperature
gauge indicates approximately
90 °C (195 °F).
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
full cold mark.
5. Replace the pressure cap
tightly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 379
2. Remove the two rear lamp
assembly screws.
3. Pull the rear lamp assembly
outboard away from the box
side until the retainers release.
There will be a noise when the
retainers release. 4. Pull the rear lamp assembly
straight back to remove it from
the vehicle.
5. Turn the bulb socket
counterclockwise.
6. Pull the bulb straight out from
the socket.
7. Replace the bulb, then insert
the bulb socket into the rear
lamp assembly and turn
clockwise. 8. Verify the retainer ring of
attachment stud is pulled away
from lamp. If the retainer ring is
out of position, it will not
engage. Reset the retainer by
pulling it forward with a tool.
9. Push the rear lamp assembly
straight in until it is seated
against the vehicle.
10. Make sure the rear lamp
assembly is flush with the
box side.
11. Reinstall the two rear lamp
assembly screws.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
380 Vehicle Care
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp
1. Cargo Lamp Bulbs
2. Center High-Mounted
Stoplamp (CHMSL) Bulb To replace one of these bulbs:
1. Remove the two screws and lift
off the lamp assembly.
2. Turn the bulb socket
counterclockwise and pull it
straight out.
3. Pull the bulb straight out from
the socket. 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 left 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.