2020 GMC SIERRA AC low pressure

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Driving and Operating 313
3. Activate the tool near the valvestem or adjust the air pressure
of this tire until the horn chirps
and all working vehicle and
trailer lights flash.
The process stops without
saving the sensor locations if
this step takes more than
two minutes.
4. Move to the next tire and repeat Step 3 for each sensor.
The horn chirps twice when all
sensors are completed.
5. Return to the vehicle to complete the setup.
Maintenance Reminders
To set up maintenance reminders,
touch the Trailer Maintenance icon.
Select Yes to set up the
maintenance reminders for the
Trailer Profile. Follow the on-screen
prompts. The maximum number of
reminders is 50. Select No to return
to the previous screen.
Towing Assistance
If the Transparent Trailer feature is
available, touch the Towing
Assistance icon to set up
transparent trailer.
Touch Yes to begin set up or touch
No to return to the previous screen.
Follow the on-screen instructions.
A rear trailer camera must be
mounted on the trailer and
electrically connected to the vehicle
before transparent trailer feature
can be used. See Assistance
Systems for Parking or Backing
0 257.
Trailer dimensions must be in range
and transparent trailer must be
calibrated prior to use.
Transparent Trailer Setup
To complete setup for transparent
trailer: 1. Select the number of axles on the trailer. 2. Enter trailer dimensions
.Trailer Length: 300 cm
(118.1 in) 970 cm (381.8
in). Measure from center of
coupler to furthest rear
point on the trailer.
. Trailer Width: 120 cm (47.2
in) 260 cm (102.3 in).
Measure from left edge to
right edge.
. Trailer Height: 1 cm
(.39 in) –450 cm (177.1 in).
Measure from ground to
tallest point.
. Hitching Point Length: 180
cm (70.8 in) –970
cm (381.8 in). Measure from
center of coupler to middle
of tires.
. Trailer Tongue Length: 50
cm (119.6 in) –220
cm (86.6 in). Measure from
center of coupler to trailer
front wall.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
316 Driving and Operating
Trailer
1. Trailer Tire Pressure/Temperature
2. Mileage of Trailer
Mileage
The mileage accumulated while this
Trailer Profile is active will display.
Touch mileage to edit.
Tire Pressure and Temperature
If the TTPMS sensor-to-vehicle
learn process was completed, the
status view will display the current
tire pressure and temperature of the
trailer tires related to the active Trailer Profile. If a tire’
s pressure is
low or high, the color of the
pressure value will be amber. If a
sensor malfunctions, the values are
dashed lines. If the screen displays
“Service Tire Pressure Monitoring
System”, the vehicle needs to be
taken to a dealer for service.
Maintenance
1. List of Maintenance
Reminders
2. Add a New Maintenance Reminder
The Maintenance Status view
displays reminders. Touch a
reminder to edit.
Touch + New Maintenance
Reminder to go to the Select New
Reminder view.
The progress bar turns yellow when
the maintenance item reaches 90%
complete.
The progress bar turns red when
the maintenance item reaches
100% complete.
Maintenance Notifications
.Touch Service Complete to reset
the maintenance reminder.
. Touch Remind Me Later to delay
the reminder.
. Touch X next to Upcoming Alerts
(90%) to dismiss the alert. It will
not appear again.
. Touch X next to Maintenance
Due (100%) to delay the alert to
the next ignition cycle.
Always follow all of the maintenance
instructions that came with your
trailer.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
318 Driving and Operating
associated with Custom Trailer
Profiles in addition to default
checklists.
Trailers View
Touch the Trailers tab to view,
activate, create, edit, or delete
Trailer Profiles.
If a trailer is connected, touch the
Trailer Profile name to activate a
Trailer Profile.
There can be up to five Custom
Trailer Profiles on the vehicle.
The Custom Trailer Profiles and
Guest Trailer are in order of the
most frequently used.
All personalization features are
based on the settings for each
driver in vehicle personalization.
The list of Trailer Profiles is based
on vehicle personalization settings.
Guest Trailer
If the Guest Trailer Profile is the
active Trailer Profile, trailer
detection, connections status, theft,
and the Tow/Haul reminder alerts
can be sent. The system will nottrack total mileage or fuel economy,
but the system will track trip mileage
and fuel economy if the Guest
Trailer Profile is active. The Trailer
Tire Pressure Monitoring System or
maintenance reminders cannot be
set up for a Guest Trailer Profile.
The Guest Trailer Profile cannot be
edited.
Touch
pto learn more about the
Guest Trailer option.
No Trailer Connected
When there is no trailer connected,
Trailer Profiles cannot be activated
but most options can be edited.
Trailer Brake Gain Memory
The system can memorize the brake
gain setting of a Trailer Profile or a
Guest Trailer Profile. When a Trailer
Profile or Guest Trailer Profile is
selected, and a brake gain setting is
set for that Trailer Profile, a quick
notice will appear to indicate that
the system has recalled that
profile’s brake gain setting. If a Trailer Profile is already active
and the brake gain setting had been
set for that Trailer Profile, the quick
notice will trigger whenever the
ignition is turned on.
If there was an error in setting the
brake gain for a Trailer Profile, there
will be a notification. This pop-up
will not appear if the Guest Trailer
Profile is active or if there is no
trailer connected.
Trailer brake gain should be set for
a specific trailering condition and
must be adjusted anytime vehicle
loading, trailer loading, or road
surface conditions change.
Editing a Trailer Profile
Trailer Profile View
Touch to edit any of the following
options in the Trailer Profile view:
.
Trailer Name
. Towing Assistance Setup
. Tire Pressure Setup
. Trailer Maintenance
. Mileage

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 339
1. Remote Negative (–) Location.See Jump Starting - North
America 0419.
2. Positive (+) Terminal (Under Cover). See Jump Starting -
North America 0419.
3. Battery - North America 0358.
4. Engine Air Cleaner/Filter 0344.
5. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil 0339.
6. Engine Cooling Fan (Out of View). See Cooling System
0 346.
7. Power Steering Fluid Reservoir. See Power Steering
Fluid 0354.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil 0339.
9. Auxiliary Battery. Battery -
North America 0358.
10. Brake Fluid Reservoir. See Brake Fluid 0357.
11. Engine Compartment Fuse
Block 0371. 12. Coolant Surge Tank and
Pressure Cap. See Cooling
System 0346.
13. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
0 354.
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
. Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section. .
Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0341.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially
prior to a long trip. The engine oil
dipstick handle is a loop. See
Engine Compartment Overview
0332 for the location.
{Warning
The engine oil dipstick handle
may be hot; it could burn you.
Use a towel or glove to touch the
dipstick handle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
346 Vehicle Care
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when driving.
Cooling System
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
The cooling system allows the
engine to maintain the correct
working temperature.
2.7L L4 Engine (L3B)
4.3L V6 Engine (LV3)
5.3L V8 Engine (L84) Shown, 5.3LV8 Engine (L82) and 6.2LV8 Engine (L87) Similar
1. Engine Electric Cooling Fans (Out of View)
2. Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan can
start up even when the engine is
not running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 347
6.6L V8 Engine (L8T)
1. Engine Cooling Fan (Outof View)
2. Coolant Surge Tank and Pressure Cap
{Warning
Do not touch heater, radiator, a/c
pipes or hoses, or other engine
parts. They can be very hot and
can burn you. Do not run the
engine if there is a leak; all
coolant could leak out. That could
(Continued)
Warning (Continued)
cause an engine fire and can
burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
seeEngine Overheating 0351.
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
(Continued)
Warning (Continued)
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.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature.
. Gives boiling protection up to
129 °C (265 °F), engine
temperature.
. Protects against rust and
corrosion.
. Will not damage aluminum parts.
. Helps keep the proper engine
temperature.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
350 Vehicle Care
Warning (Continued)
warning. The engine could catch
fire and you or others could be
burned.
{Warning
Steam 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.
Caution
Failure 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.
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
indicated mark.
5. Replace the pressure cap tightly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/10/19
Vehicle Care 361
For vehicles equipped with the Stop/
Start system:1. Install the negative battery cable to the battery
sensor stud.
2. Install the negative battery cable nut to the battery sensor
stud and tighten.
3. Turn the ignition on.
For vehicles not equipped with the
Stop/Start system: 1. Install the negative battery cable clamp to the negative
battery post.
2. Tighten the negative battery cable nut.
3. Turn the ignition on.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to Maintenance Schedule
0 442 to determine when to check
the lubricant.
1. Fill Plug
2. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface.
If the level is below the bottom of
the fill plug (1) hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug (1) hole. Use
care not to overtighten the plug. When to Change Lubricant
Refer to
Maintenance Schedule
0 442 to determine how often to
change the lubricant.
What to Use
Refer to Recommended Fluids and
Lubricants 0453 to determine what
kind of lubricant to use.
Front Axle
When to Check Lubricant
It is not necessary to regularly
check the front axle fluid unless a
leak is suspected or an unusual
noise is heard. A fluid loss could
indicate a problem. Have it
inspected and repaired. This service
can be complex. See your dealer.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water
can overcome the seals and
contaminate the fluid. Contaminated
fluid will decrease the life of the
transfer case and/or drive axles and
should be replaced.