2015 GMC SIERRA run flat

Black plate (21,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
In Brief 1-21
The low tire pressure warning light
alerts to a significant loss in
pressure of one of the vehicle's
tires. If the warning light comes on,
stop as soon as possible and inflate
the tires to the recommended
pressure shown on the Tire and
Loading Information label. See
Vehicle Load Limits on page 9-15.
The warning light will remain on until
the tire pressure is corrected.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
may be an early indicator that the
tire pressures are getting low and
the tires need to be inflated to the
proper pressure.
The TPMS does not replace normal
monthly tire maintenance. Maintain
the correct tire pressures.
SeeTire Pressure Monitor System
on page 10-61.Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays a DIC message when
it is necessary to change the engine
oil and filter. The oil life system
should be reset to 100% only
following an oil change.
Resetting the Oil Life System
1. Display OIL LIFE REMAINING
on the DIC. See Driver
Information Center (DIC) on
page 5-27.
2. Press and hold
Vfor several
seconds. 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 OIL LIFE
REMAINING on the DIC. If the
display shows 100%, the system
is reset.
See Engine Oil Life System on
page 10-11.
E85 or FlexFuel
Vehicles with a yellow fuel cap can
use either unleaded gasoline or
ethanol fuel containing up to 85%
ethanol (E85). See E85 or FlexFuel
on page 9-65. For all other vehicles,
use only the unleaded gasoline
described under Fuel on page 9-63.
Driving for Better Fuel
Economy
Driving habits can affect fuel
mileage. Here are some driving tips
to get the best fuel economy
possible.
.Avoid fast starts and accelerate
smoothly.
.Brake gradually and avoid
abrupt stops.

Black plate (70,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
9-70 Driving and Operating
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
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 on page 9-39.
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 on
page 10-21.
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.

Black plate (87,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-87
The vehicle may have a different
size spare tire than the road tires
originally installed on the vehicle.
This spare tire was developed for
use on this vehicle, so it is all right
to drive on it. If the vehicle has
four-wheel drive and a different size
spare tire is installed, drive only in
two-wheel drive.
After installing the spare tire on the
vehicle, stop as soon as possible
and check that the spare tire is
correctly inflated.
Have the damaged or flat road tire
repaired or replaced and installed
back onto the vehicle as soon as
possible so the spare tire will be
available in case it is needed again.
Do not mix tires and wheels of
different sizes, because they will not
fit. Keep your spare tire and its
wheel together. If the vehicle has a
spare tire that does not match the
original road tires and wheels in size
and type, do not include the spare in
the tire rotation.Jump Starting
For more information about the
vehicle battery, seeBattery on
page 10-29.
If the vehicle's battery (or batteries)
has run down, you may want to use
another vehicle and some jumper
cables to start your vehicle. Be sure
to use the following steps to do it
safely.
{Warning
Batteries can hurt you. They can
be dangerous because:
.They contain acid that can
burn you.
.They contain gas that can
explode or ignite.
.They contain enough
electricity to burn you.
If you do not follow these steps
exactly, some or all of these
things can hurt you.
{Caution
Ignoring these steps could result
in costly damage to the vehicle
that would not be covered by the
vehicle warranty. Trying to start
the vehicle by pushing or pulling it
will not work, and it could damage
the vehicle.
1. Check the other vehicle. It must have a 12-volt battery with a
negative ground system.
{Caution
If the other vehicle does not have
a 12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. If you have a vehicle with a diesel engine with two batteries,
you should know before you

Black plate (91,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-91
6.6L
‐ To the negative (−) post on
the auxiliary battery, on the
vehicle with the dead battery.
11. Start the vehicle with the good battery and run the engine for a
while.
12. Try to start the vehicle that had the dead battery. If it will not
start after a few tries, it
probably needs service.
{Caution
If the jumper cables are
connected or removed in the
wrong order, electrical shorting
may occur and damage the
vehicle. The repairs would not be
covered by the vehicle warranty.
Always connect and remove the
jumper cables in the correct order,
making sure that the cables do
not touch each other or other
metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
Towing the Vehicle
{Caution
Incorrectly towing a disabled
vehicle may cause damage. The
damage would not be covered by
the vehicle warranty.
Have the vehicle towed on a flatbed
car carrier. A wheel lift tow truck
could damage the vehicle.
Consult your dealer or a
professional towing service if the
disabled vehicle must be towed.
Recreational Vehicle
Towing
Recreational vehicle towing means
towing the vehicle behind another
vehicle, such as a motor home. The
two most common types of
recreational vehicle towing are
dinghy and dolly towing. Dinghy
towing is towing the vehicle with all
four wheels on the ground. Dolly

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