2017 GMC SIERRA DENALI cooling

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 373
5.3L V8 Engine Shown, 4.3L
V6 Engine and 6.2L V8 Engine
Similar
1. Coolant Surge Tank
2. Coolant Surge Tank
Pressure Cap
3. Engine Electric Cooling
Fans (Out of View)
{ Warning
An electric engine cooling fan can
start even when the engine is not
running. To avoid injury, always
(Continued) Warning (Continued) keep hands, clothing, and tools
away from any engine
cooling fan.
6.0L V8 Engine
1. Coolant Surge Tank
2. Coolant Surge Tank
Pressure Cap
3. Engine Belt-Driven Cooling
Fan (Out of View){ WarningHeater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
CautionUsing coolant other than
DEX-COOL ®
can cause
premature engine, heater core,
or radiator corrosion. In addition,
the engine coolant could require
changing sooner. Any repairs
would not be covered by the
vehicle warranty. Always use
DEX-COOL (silicate-free) coolant
in the vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
374 Vehicle Care
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,
see Engine Overheating 0 376 .
What to Use
{ WarningAdding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
(Continued) Warning (Continued) 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.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
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. CautionIf improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
mixture can freeze and crack
engine cooling parts. The repairs
would not be covered by the
vehicle warranty. Use only the
proper mixture of engine coolant
for the cooling system. See
Recommended Fluids and
Lubricants 0 464 .
Never dispose of engine coolant by
putting it in the trash, or by pouring
it on the ground, or into sewers,
streams, or bodies of water. Have
the coolant changed by an
authorized service center, familiar
with legal requirements regarding
used coolant disposal. This will help
protect the environment and your
health.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 375Checking Coolant The coolant surge tank is located in
the engine compartment on the
passenger side of the vehicle. See
Engine Compartment Overview
0 359 .
The vehicle must be on a level
surface when checking the coolant
level.
5.3L V8 Shown, 4.3L V6, 6.0L V8,
and 6.2L V8 Similar
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, wait until it cools down. The
coolant level should be at or above the FULL COLD mark. If it is not,
there may be a leak in the cooling
system.
If coolant is visible but the coolant
level is not at or above the FULL
COLD mark, see “ How to Add
Coolant to the Coolant Surge Tank
for Gasoline Engines, ” following.
How to Add Coolant to the
Coolant Surge Tank for
Gasoline Engines If the vehicle has a diesel engine,
see “ Cooling System ” in the
Duramax diesel supplement for the
proper coolant fill procedure.
{ Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine. CautionThis vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
{ WarningSteam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.
If no coolant is visible in the surge
tank, add coolant.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
376 Vehicle Care
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.
6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 – 6.
Caution
If the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured. Engine Overheating If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
CautionRunning the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See Engine Coolant
Temperature Gauge 0 138 .
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
See Engine Cooling System
Messages 0 159 and Engine Power
Messages 0 160 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 377If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 478 .
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be
running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{ Warning
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
(Continued) Warning (Continued) off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam is Coming from
the Engine Compartment The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem. If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.
Climbs a long hill on a hot day.
.
Stops after high-speed driving.
.
Idles for long periods in traffic.
.
Tows a trailer; see Trailer Towing
0 323 .
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the
highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off
the road, shift to P (Park) or
N (Neutral) and let the
engine idle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
378 Vehicle Care If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.
If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down. 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.
See Engine Oil 0 364 .
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
Vehicle Care 379This 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. Power Steering Fluid
(1500 Series) The vehicle has electric power
steering and does not use power
steering fluid.
Power Steering Fluid
(2500/3500 Series)
See Engine Compartment Overview
0 359 for reservoir location.
When to Check Power Steering
Fluid It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired. Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid To check the power steering fluid:
1. Turn the ignition off and let the
engine compartment
cool down.
2. Wipe the cap and the top of the
reservoir clean.
3. Unscrew the cap and wipe the
dipstick with a clean rag.
4. Replace the cap and
completely tighten it.
5. Remove the cap again and
look at the fluid level on the
dipstick.
The level should be between the
ADD and FULL marks. If necessary,
add only enough fluid to bring the
level up to the hashed area between
the ADD and FULL marks.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-9955992) - 2017 - crc - 4/18/17
394 Vehicle Care
Fuses Usage
1 Trailer brake Fuses Usage
2 Trailer battery
3 ABS pump Fuses Usage
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