engine overheat GMC SIERRA 2015 Owner's Guide

Black plate (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-21
Light-Duty
Coolant Surge Tank
Pressure CapHeavy-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.
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 on page 5-13.

Black plate (22,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-22 Vehicle Care
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
on page 5-33andEngine Power
Messages on page 5-34.
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program on
page 13-5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
Then check to see if the engine
cooling fan is running. If the engine
is overheating, the fan should be
running. If it is not, do not continue
to run the engine and have the
vehicle serviced.{Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty.
See Overheated Engine
Protection Operating Mode on
page 10-23 for information on
driving to a safe place in an
emergency.
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. Turn it off
and get everyone away from the
vehicle until it cools down. Wait
(Continued)
Warning (Continued)
until there is no sign of steam or
coolant before you open
the hood.
If you keep driving when the
vehicles 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.
SeeOverheated Engine
Protection Operating Mode on
page 10-23 for information on
driving to a safe place in an
emergency.

Black plate (23,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-23
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; seeTrailer Towing
on page 9-71.
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.
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. Also, see
“Overheated
Engine Protection Operating Mode”
following.
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

Black plate (24,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-24 Vehicle Care
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
attempting any repair. Repair the
cause of coolant loss, change the
oil, and reset the oil life system.
SeeEngine Oil on page 10-8.
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.
This 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
fans, 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 normaland 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)

Black plate (41,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-41
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.
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.

Black plate (4,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
i-4 INDEX
Driving (cont'd)Drunk . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
For Better Fuel Economy . . . . . 1-21
Hill and Mountain Roads . . . . . . 9-11
If the Vehicle is Stuck . . . . . . . . . 9-14
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road . . . . . . . . . . . . . . . . . . . . . . 9-6
Off-Road Recovery . . . . . . . . . . . . 9-5
Vehicle Load Limits . . . . . . . . . . . 9-15
Wet Roads . . . . . . . . . . . . . . . . . . . 9-11
Winter . . . . . . . . . . . . . . . . . . . . . . . . 9-12
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 8-1
Dual Tire
Rotation . . . . . . . . . . . . . . . . . . . . 10-67
E
E85 or FlexFuel . . . . . . . . . . . . . . . 9-65
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . 9-88
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-41
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-41 Electrical System (cont'd)
Instrument Panel
Fuse Block . . . . . . . . . 10-45, 10-48
Overload . . . . . . . . . . . . . . . . . . . 10-40
Emergency OnStar
®. . . . . . . . . . . . . . . . . . . . . . 14-2
Engine Air Cleaner/Filter . . . . . . . . . . . 10-15
Check and Service EngineSoon Light . . . . . . . . . . . . . . . . . . 5-18
Compartment Overview . . . . . . . 10-5
Coolant . . . . . . . . . . . . . . . . . . . . . 10-18
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 5-13
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 5-24
Cooling System . . . . . . . . . . . . . 10-17
Cooling System Messages . . . 5-33
Drive Belt Routing . . . . . . . . . . . . 12-4
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-32
Fan . . . . . . . . . . . . . . . . . . . . . . . . . 10-24
Heater . . . . . . . . . . . . . . . . . . . . . . . . 9-28
Oil Life System . . . . . . . . . . . . . .10-11
Oil Messages . . . . . . . . . . . . . . . . . 5-34
Oil Pressure Gauge . . . . . . . . . . 5-12
Overheated Protection Operating Mode . . . . . . . . . . . 10-23 Engine (cont'd)
Overheating . . . . . . . . . . . . . . . . 10-21
Power Messages . . . . . . . . . . . . . 5-34
Pressure Light . . . . . . . . . . . . . . . . 5-25
Running While Parked . . . . . . . . 9-33
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-26
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-8
Equipment, Towing . . . . . . . . . . . . 9-78
Event Data Recorders . . . . . . . . 13-14
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-8
Extender, Safety Belt . . . . . . . . . . 3-15
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2
F
Fan Engine . . . . . . . . . . . . . . . . . . . . . . 10-24
Fast Idle System . . . . . . . . . . . . . . . 9-27
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . 1-8
Filter, Engine Air Cleaner . . . . . . . . . 10-15
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-2
Flashers, Hazard Warning . . . . . . 6-4
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-74 Changing . . . . . . . . . . . . . . . . . . . 10-76

Black plate (9,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
INDEX i-9
OnStar®Security . . . . . . . . . . . . . . 14-3
OnStar®Vehicle
Diagnostics . . . . . . . . . . . . . . . . . . 14-6
Operating Mode Overheated EngineProtection . . . . . . . . . . . . . . . . . 10-23
Ordering
Service Publications . . . . . . . . .13-11
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . . . 10-23
Overheating, Engine . . . . . . . . . . 10-21
P
Park Shifting Into . . . . . . . . . . . . . . . . . . . 9-30
Shifting Out of . . . . . . . . . . . . . . . . 9-31
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . 9-47
Brake and P (Park)Mechanism Check . . . . . . . . 10-34
Over Things That Burn . . . . . . . 9-32 Parking or Backing
Assistance Systems . . . . . . . . . . 9-56
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . 5-17
Passenger Compartment Air Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 8-5
Passenger Sensing System . . . 3-24
Perchlorate Materials
Requirements, California . . . . . 10-3
Personalization Vehicle . . . . . . . . . . . . . . . . . . . . . . . 5-42
Pickup Conversion to Chassis Cab . . . . . . . . . . . . . . . . . 9-92
Power Door Locks . . . . . . . . . . . . . . . . . . . . 2-9
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . 2-14
Outlets . . . . . . . . . . . . . . . . . . . . . . . . 5-5
Protection, Battery . . . . . . . . . . . . . 6-9
Retained Accessory (RAP) . . . 9-29
Seat Adjustment . . . . . . . . . . . . . . . 3-3
Steering Fluid . . . . . . . . . . . . . . . 10-24
Windows . . . . . . . . . . . . . . . . . . . . . 2-19
Pregnancy, Using Safety Belts . . . . . . . . . . . . . . . . . . . . . . . . . 3-15
Privacy
Vehicle Data Recording . . . . . 13-14 Program
Courtesy Transportation . . . . . . 13-8
Proposition 65 Warning, California . . . . . . . . . . . . . . . . . . . . . 10-2
R
Radio FrequencyIdentification (RFID) . . . . . . . . . 13-12
Radio Frequency
Statement . . . . . . . . . . . . . . . . . . . 13-12
Reading Lamps . . . . . . . . . . . . . . . . . 6-7
Rear Axle . . . . . . . . . . . . . . . . . . . . . 10-31 Locking . . . . . . . . . . . . . . . . . . . . . . . 9-52
Rear Seats . . . . . . . . . . . . . . . . . . . . . 3-9
Rear Windows . . . . . . . . . . . . . . . . . 2-22
Rearview Mirrors Automatic Dimming . . . . . . . . . . . 2-19
Reclining Seatbacks . . . . . . . . . . . . 3-4
Recommended Fluids and
Lubricants . . . . . . . . . . . . . . . . . . . 11-12
Records Maintenance . . . . . . . . . . . . . . . . .11-16
Recreational Vehicle
Towing . . . . . . . . . . . . . . . . . . . . . . 10-91
Reimbursement Program, GM Mobility . . . . . . . . . . . . . . . . . . 13-5