2019 GMC SIERRA DENALI engine overheat

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
Vehicle Care 325
Automatic Transmission
Fluid When to Check and Change
Automatic Transmission Fluid It is usually not necessary to check
the transmission fluid level. The only
reason for fluid loss is a
transmission leak or overheated
transmission. This vehicle is not
equipped with a transmission fluid
level dipstick. There is a special
procedure for checking and
changing the transmission fluid in
these vehicles. Because this
procedure is difficult, this should be
done at the dealer. Contact the
dealer for additional information or
the procedure can be found in the
service manual. See Publication
Ordering Information 0 442 .
Caution
Use of the incorrect automatic
transmission fluid may damage
the vehicle, and the damage may
(Continued) Caution (Continued) not be covered by the vehicle
warranty. Always use the correct
automatic transmission fluid. See
Recommended Fluids and
Lubricants 0 425 .
Change the fluid and filter at the
scheduled maintenance intervals
listed in Maintenance Schedule
0 415 . Be sure to use the
transmission fluid listed in
Recommended Fluids and
Lubricants 0 425 .
Engine Air Filter Life
System When to Change the Engine
Air Filter
When the “ Replace at Next Oil
Change ” message displays, the
engine air filter should be replaced
at the time of the next engine oil
change. When the “ Replace Engine
Air Filter Now ” message displays,
the engine air filter should be replaced as soon as possible. Reset
the engine air filter life system after
the engine air filter is replaced. See
your dealer for service and to reset
the system.
If equipped, this feature provides an
indication of when to change the
engine air filter. It is based on
driving conditions, which can cause
when to change to vary greatly. It is
possible an air filter change may not
be indicated for up to four years.
How to Reset the Engine Air
Filter Life System To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the
DIC.
See Driver Information Center
(DIC) (Midlevel and Uplevel)
0 160 or Driver Information
Center (DIC) (Base Level)
0 159 .
3. Press
T to move to the Reset/
Disable display area. Select
Reset then press
V .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
328 Vehicle Care
5.3L V8 Engine (L84) Shown, 5.3L
V8 Engine (L82) and 6.2L
V8 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. { WarningDo 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
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,
see Engine Overheating 0 331 . What to Use
{ 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.
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
330 Vehicle Care 3. Connect the vehicle to a
battery charger.
4. Turn the ignition on for Key
Access vehicles or to Service
Only for Keyless Access
vehicles.
See Ignition Positions (Key
Access) 0 217 or Ignition
Positions (Keyless Access)
0 219 .
5. Turn off the air conditioning.
6. Set the parking brake.
7. At the same time, press the
accelerator and the brake for
automatic transmission
vehicles for two seconds, then
release.
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
2 minutes, and repeat Steps 3-7.
Listen for pump activation and
movement of the control valves
while watching the level of the
coolant in the surge tank. If the tank empties, turn the ignition off,
carefully remove the surge tank cap,
refill to the COLD FILL mark, and
repeat Steps 3-6. The fill and air
removal process will run for
approximately 10 minutes.
How to Add Coolant to the
Coolant Surge Tank for
Gasoline Engines Except L3B If the vehicle has a diesel engine,
see “ Cooling System ” in the
Duramax diesel supplement for the
proper coolant fill procedure.
{ WarningSpilling coolant on hot engine
parts can burn you. Coolant
contains ethylene glycol and it will
burn if the engine parts are hot
enough. { 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
Vehicle Care 331CautionFailure 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. 6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 – 6.
CautionIf the pressure cap is not tightly
installed, coolant loss and 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.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
332 Vehicle Care 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 0 145 .
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 437 .
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
2.7L L4, 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
{ 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.
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. The 2.7L engine will shut down
automatically if the ENGINE
OVERHEATED STOP ENGINE
message displays.
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
0 281 .
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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
Vehicle Care 3333. 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.
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. CautionAfter 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.
See Engine Oil 0 321 .
Engine Fan 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

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-1500-11698638) - 2019 - crc - 5/15/18
350 Vehicle Care 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 and Circuit
Breakers The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by
electrical problems. { DangerFuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit
breakers. Use of an oversized
fuse or circuit breaker can result
in a vehicle fire. You and others
could be seriously injured or
killed.
To check a fuse, look at the
silver-colored band inside the fuse.
If the band is broken or melted,
replace the fuse. Be sure to 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
possible. 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 passenger side of the vehicle.
Lift the cover to access the fuse
block.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-1500-11698638) - 2019 - crc - 5/16/18
462 Index Door (cont'd)
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Power Locks . . . . . . . . . . . . . . . . . . . . 45
Drive Belt Routing, Engine . . . . . . 432
Driver Assistance Systems . . . . . 253
Driver Information
Center (DIC) . . . . . . . . . . . . . 159, 160
Driver Mode Control . . . . . . . . . . . . 246
Driver Mode Control Light . . . . . . 156
Driving
Assistance Systems . . . . . . . . . . 260
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 276
Defensive . . . . . . . . . . . . . . . . . . . . . 198
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 198
For Better Fuel Economy . . . . . . . 29
Hill and Mountain Roads . . . . . . 206
If the Vehicle is Stuck . . . . . . . . . 208
Loss of Control . . . . . . . . . . . . . . . 200
Off-Road . . . . . . . . . . . . . . . . . . . . . 200
Off-Road Recovery . . . . . . . . . . . 199
Vehicle Load Limits . . . . . . . . . . . 209
Wet Roads . . . . . . . . . . . . . . . . . . . 205
Winter . . . . . . . . . . . . . . . . . . . . . . . . 206
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 190 E E85 or FlexFuel . . . . . . . . . . . . . . . . 272
Electric Parking Brake . . . . . . . . . . 241
Electric Parking Brake Light . . . . 152
Electrical Equipment,
Add-On . . . . . . . . . . . . . . . . . . . . . . . 306
Electrical System
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 350
Fuses and Circuit Breakers . . . 350
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . 354, 356
Overload . . . . . . . . . . . . . . . . . . . . . 349
Electronic Stability Control
(ESC) Off Light . . . . . . . . . . . . . . . . 155
Emergency
OnStar . . . . . . . . . . . . . . . . . . . . . . . 448
Engine
Air Cleaner/Filter . . . . . . . . . . . . . 326
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 149
Compartment Overview . . . . . . . 316
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 145
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . 155
Cooling System . . . . . . . . . . . . . . . 327
Drive Belt Routing . . . . . . . . . . . . 432 Engine (cont'd)
Exhaust . . . . . . . . . . . . . . . . . . . . . . 228
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Heater . . . . . . . . . . . . . . . . . . . . . . . . 223
Oil Life System . . . . . . . . . . . . . . . 323
Oil Pressure Gauge . . . . . . . . . . 144
Oil Pressure Light . . . . . . . . . . . . 157
Overheated Protection
Operating Mode . . . . . . . . . . . . . 333
Overheating . . . . . . . . . . . . . . . . . . 331
Power Messages . . . . . . . . . . . . . 167
Running While Parked . . . . . . . . 229
Starting . . . . . . . . . . . . . . . . . . . . . . . 221
Engine Air Filter Life System . . . . 325
Entry Lighting . . . . . . . . . . . . . . . . . . . 184
Equipment, Towing . . . . . . . . . . . . . 285
Event Data Recorders . . . . . . . . . . 445
Exit Lighting . . . . . . . . . . . . . . . . . . . . 184
Extended Parking . . . . . . . . . . . . . . . 228
Extender, Seat Belt . . . . . . . . . . . . . . 84
Exterior Cargo Lamps . . . . . . . . . . 182
Exterior Lamp Controls . . . . . . . . . 176
Exterior Lamps Off Reminder . . . 178
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . . . 185