
GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Driving and Operating 187
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Starting Procedure
1. Turn the ignition key to START.When the engine starts, let go
of the key. The idle speed will
go down as the engine gets
warm. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently to allow the
oil to warm up and lubricate all
moving parts.
When the low fuel warning light
is on and the FUEL LEVEL
LOW message is displayed in
the Driver Information Center
(DIC), hold the ignition switch
in the START position to
continue engine cranking.
Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds,
especially in very cold weather
(below −18 °C or 0 °F), it could
be flooded with too much
gasoline. Try pushing the
accelerator pedal all the way to
the floor and holding it there
while holding the key in START
for up to 15 seconds. Wait at
least 15 seconds between each
try, to allow the cranking motor
to cool down. When the engine
starts, let go of the key and accelerator. If the vehicle starts
briefly but then stops again, do
the same thing. This clears the
extra gasoline from the engine.
Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
Fast Idle System
If equipped, this feature is available
only with cruise control. The manual
fast idle switch is operated using the
cruise control buttons on the left
side of the steering wheel.
This system can be used to
increase engine idle speed
whenever the following conditions
are met:
.
The parking brake is set.
. The brake pedal is not pressed.
. The vehicle must not be moving
and the accelerator must not be
pressed.
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
188 Driving and Operating
To control the fast idle:
.To enable the Fast Idle System,
press and release the cruise
control on/off button and ensure
that the switch indicator light
is lit.
. Press and release the cruise
control SET- button. Engine
speed will be held at
approximately 1200 rpm.
One of the following actions will turn
off the fast idle:
. Pressing the brake.
. Selecting the cruise control
cancel button.
. Releasing the parking brake.
. Moving the transmission shift
lever out of P (Park) or
N (Neutral).
. Selecting the cruise control on/
off button when it was
previously on.
. Pressing the cruise control SET-
button a second time. .
Pressing the accelerator more
than one-quarter of the
way down.
. Turning the ignition switch to the
LOCK/OFF position.
Engine Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
−18 °C (0 °F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist,
which will prevent engine coolant
heater operation at temperatures
above −18 °C (0 °F).
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
To Use the Engine Coolant
Heater
1. Turn off the engine. 2. Open the hood and unwrap the
electrical cord. The cord is
secured to the driver side
fender with a clip, next to the
engine compartment fuse
block. Carefully remove the
wire tie that bundles the
electrical plug. Do not cut the
electrical cord.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.
. Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
(Continued)
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Driving and Operating 189
Warning (Continued)
function. An ungrounded
outlet could cause an
electric shock.
. Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension
cord in good operating
condition, or using a
damaged heater or
extension cord, could make
it overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
(Continued)
Warning (Continued)
vehicle. Possible heater
cord and thermostat
damage could occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it
away from moving engine
parts. If you do not, it could be
damaged.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Retained Accessory
Power (RAP)
The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
. Audio System
. Power Windows
. OnStar System (if equipped)
. Sunroof (if equipped)
These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes or until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened.
Accessory Power Outlets (APOs)
The vehicle may have APOs in
several locations. See Power
Outlets 0102.
The APOs in the console or center
seat position are powered by RAP.
They will continue to work for up to
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Driving and Operating 191
Warning (Continued)
And, if you leave the vehicle with
the engine running, it could
overheat and even catch fire. You
or others could be injured. Do not
leave the vehicle with the engine
running unless you have to.
If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the
parking brake is firmly set before
you leave it. After you move the shift
lever into P (Park), hold the regular
brake pedal down. Then, see if you
can move the shift lever away from
P (Park) without first pulling it toward
you. If you can, it means that the
shift lever was not fully locked into
P (Park).
Torque Lock
If you are parking on a hill and you
do not shift the transmission into
P (Park) properly, the weight of the
vehicle may put too much force on
the parking pawl in the
transmission. You may find it difficult to pull the shift lever out of P (Park).
This is called torque lock. To
prevent torque lock, set the parking
brake and then shift into P (Park)
properly before you leave the driver
seat. To find out how, see
Shifting
Into Park 0190.
When you are ready to drive, move
the shift lever out of P (Park) before
you release the parking brake.
If torque lock does occur, you may
need to have another vehicle push
yours a little uphill to take some of
the pressure from the parking pawl
in the transmission. You will then be
able to pull the shift lever out of
P (Park).
Shifting out of Park
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is
designed to:
. Prevent ignition key removal
unless the shift lever is in
P (Park). .
Prevent movement of the shift
lever out of P (Park), unless the
ignition is in ON/RUN and the
regular brake pedal is applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9 volt) battery.
If the vehicle has an uncharged
battery or a battery with low voltage,
try charging or jump starting the
battery. See Jump Starting - North
America 0326.
To shift out of P (Park): 1. Apply the brake pedal.
2. Move the shift lever to the desired position.
If you still are unable to shift out of
P (Park): 1. Ease the pressure on the shift lever.
2. While holding down the brake pedal, press the shift lever all
the way into P (Park).
3. Move the shift lever to the desired position.
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
230 Driving and Operating
Driving on Grades
Reduce speed and shift to a lower
gearbefore starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode 0199.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few minutes before turning the engine
off. If the overheat warning comes
on, see
Engine Overheating 0270.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular
brakes until the chocks absorb
the load. 4. Reapply the brake pedal. Then
apply the parking brake and
shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule 0346.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Driving and Operating 247
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0115.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle
systems. This could affect vehicle
operation and cause a crash.
Such devices may also access
information stored in the vehicle’s
systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and
would not be covered by the
vehicle warranty. Always check
with your dealer before adding
electrical equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see
Servicing the Airbag-Equipped
Vehicle 071 and Adding Equipment
to the Airbag-Equipped Vehicle
0 72.
For information on wiring auxiliary
switches, see www.gmupfitter.com
or contact your dealer.
Adding a Snow Plow or
Similar Equipment
Caution
Do not exceed 64 km/h (40 mph)
with a snow plow mounted to the
vehicle. The vehicle could
overheat and be damaged.
Before installing a snow plow on the
vehicle, here are some things you
need to know:
Caution
If the vehicle does not have the
snow plow prep package, adding
a plow can damage the vehicle,
and the repairs would not be
covered by warranty. Unless the
vehicle was built to carry a snow
plow, do not add one to the
vehicle. If the vehicle has the
snow plow prep package, called
RPO VYU, then the payload the
vehicle can carry will be reduced (Continued)
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Vehicle Care 251
Vehicle Care
General Information
General Information . . . . . . . . . . 252
California Proposition65 Warning . . . . . . . . . . . . . . . . . 252
California Perchlorate Materials Requirements . . . . . 252
Accessories and Modifications . . . . . . . . . . . . . . . . 252
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 253
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 254
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 255
Engine Oil . . . . . . . . . . . . . . . . . . . . 258
Engine Oil Life System . . . . . . . 261
Automatic Transmission Fluid (6 Speed Transmission) . . . . . 261
Automatic Transmission Fluid (8 Speed Transmission) . . . . . 264
Engine Air Cleaner/Filter . . . . . . 265
Cooling System . . . . . . . . . . . . . . 266
Engine Coolant . . . . . . . . . . . . . . . 267
Engine Overheating . . . . . . . . . . 270
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 272
Engine Fan . . . . . . . . . . . . . . . . . . . 272 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 273
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 273
Washer Fluid . . . . . . . . . . . . . . . . . 274
Brakes . . . . . . . . . . . . . . . . . . . . . . . 275
Brake Fluid . . . . . . . . . . . . . . . . . . . 275
Battery - North America . . . . . . 277
Four-Wheel Drive . . . . . . . . . . . . . 277
Front Axle . . . . . . . . . . . . . . . . . . . . 278
Rear Axle . . . . . . . . . . . . . . . . . . . . 279
Noise Control System . . . . . . . . 280
Starter Switch Check . . . . . . . . . 281
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 281
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 282
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 282
Wiper Blade Replacement . . . . 282
Glass Replacement . . . . . . . . . . 283
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 283
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 283
Halogen Bulbs . . . . . . . . . . . . . . . . 283
LED Lighting . . . . . . . . . . . . . . . . . 283 Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 284
Replacement Bulbs . . . . . . . . . . . 284
Electrical System
Electrical System Overload . . . 284
Fuses . . . . . . . . . . . . . . . . . . . . . . . . 285
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 285
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 288
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 290
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 292
All-Season Tires . . . . . . . . . . . . . . 293
Winter Tires . . . . . . . . . . . . . . . . . . 293
Low-Profile Tires . . . . . . . . . . . . . 294
All-Terrain Tires . . . . . . . . . . . . . . . 294
Tire Sidewall Labeling . . . . . . . . 294
Tire Designations . . . . . . . . . . . . . 297
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 298
Tire Pressure . . . . . . . . . . . . . . . . . 300
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . 302
Tire Pressure Monitor
System . . . . . . . . . . . . . . . . . . . . . . 302
, Q I R U P D W L R Q 3 U R Y L G H G E \

GMC Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
9234761) - 2016 - crc - 7/24/15
Vehicle Care 261
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based
on a combination of factors which
include engine revolutions, engine
temperature, and miles driven.
Based on driving conditions, the
mileage at which an oil change is
indicated can vary considerably. For
the oil life system to work properly,
the system must be reset every time
the oil is changed.
When the system has calculated
that oil life has been diminished, a
CHANGE ENGINE OIL SOON
message comes on to indicate that
an oil change is necessary. See
Engine Oil Messages0128.
Change the oil as soon as possible
within the next 1 000 km (600 mi).
It is possible that, if driving under
the best conditions, the oil life
system may indicate that an oil
change is not necessary for up to a
year. The engine oil and filter must
be changed at least once a year
and, at this time, the system must be reset. Your dealer has trained
service people who will perform this
work and reset the system. It is also
important to check the oil regularly
over the course of an oil drain
interval and keep it at the proper
level.
If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System
Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. Always reset the
engine oil life to 100% after every oil
change. It will not reset itself. To
reset the engine oil life system:
1. Display the REMAINING OIL LIFE on the DIC. See Driver
Information Center (DIC) 0123.
2. Press and hold
V. The oil life
will change to 100%. The oil life system can also be reset
as follows:
1. Turn the ignition to ON/RUN with the engine off.
2. Fully press the accelerator pedal slowly three times within
five seconds.
3. Display the REMAINING OIL LIFE on the DIC. If the display
shows 100%, the system is
reset.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started and/or the
REMAINING OIL LIFE is near 0%,
the engine oil life system has not
been reset. Repeat the procedure.
Automatic Transmission
Fluid (6 Speed
Transmission)
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
, Q I R U P D W L R Q 3 U R Y L G H G E \