2015 GMC SIERRA 1500 cooling

Black plate (12,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-12 Driving and Operating
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on flat or rolling terrain. Tips for
driving in these conditions include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the
vehicle on a long downhill slope
can cause brake overheating, can
reduce brake performance, and
could result in a loss of braking.
Shift the transmission to a lower
gear to let the engine assist the
brakes on a steep downhill slope.
{Warning
Coasting downhill in N (Neutral)
or with the ignition off is
dangerous. This can cause
overheating of the brakes and
loss of steering. Always have the
engine running and the vehicle
in gear.
.Stay in your own lane. Do not
swing wide or cut across the
center of the road. Drive at
speeds that let you stay in your
own lane.
.Be alert on top of hills;
something could be in your lane
(stalled car, accident).
.Pay attention to special road
signs (falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Drive carefully when there is snow
or ice between the tires and the
road, creating less traction or grip.
Wet ice can occur at about 0°C
(32°F) when freezing rain begins to
fall, resulting in even less traction.
Avoid driving on wet ice or in
freezing rain until roads can be
treated with salt or sand.
Drive with caution, whatever the
condition. Accelerate gently so
traction is not lost. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick, so there is even less
traction.
Try not to break the fragile traction.
If you accelerate too fast, the drive
wheels will spin and polish the
surface under the tires even more.
Traction Control should be turned
on. SeeTraction Control/Electronic
Stability Control on page 9-50.

Black plate (37,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-37
Gear before shifting from D
(Drive) to M (Manual Mode)6th 5th 4th 3rd 2nd 1st
Range after shifting from D
(Drive) to M (Manual Mode) M4 M4 M3 M2 M2 M1
Grade Braking is not available when
Range Selection Mode is active.
See Tow/Haul Mode on page 9-37.
While using Range Selection Mode,
cruise control and the Tow/Haul
Mode can be used.
If the vehicle has an exhaust brake,
it can also be used, but will not
automatically downshift the
transmission. See “Exhaust Brake”
in the Duramax diesel supplement.
{Caution
Spinning the tires or holding the
vehicle in one place on a hill
using only the accelerator pedal
may damage the transmission.
The repair will not be covered by
(Continued)
Caution (Continued)
the vehicle warranty. If you are
stuck, do not spin the tires. When
stopping on a hill, use the brakes
to hold the vehicle in place.
Low Traction Mode
Low Traction Mode assists in
vehicle acceleration when road
conditions are slippery, such as with
ice or snow. While the vehicle is at a
stop, select M2 using Range
Selection Mode. This will limit
torque to the wheels and help to
prevent the tires from spinning.
Tow/Haul Mode
Vehicles with an automatic
transmission have a Tow/Haul
Mode. The Tow/Haul Mode adjusts
the transmission shift pattern to
reduce shift cycling. This provides
increased performance, vehicle
control, and enhanced transmission
and engine cooling when driving
down steep hills or mountain
grades, towing, or hauling heavy
loads.

Black plate (72,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
9-72 Driving and Operating
4. Reapply the brake pedal. Thenapply 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 on
page 11-3. Things that are
especially important in trailer
operation are automatic
transmission fluid, engine oil, axle lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
If the vehicle is bi-fuel, see the
bi-fuel supplement.
Do not tow a trailer during break-in.
See
New Vehicle Break-In on
page 9-23.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too
heavy, the brakes may not work
(Continued)
Warning (Continued)
well or even at all. The driver and
passengers could be seriously
injured. The vehicle may also be
damaged; the resulting repairs
would not be covered by the
vehicle warranty. Pull a trailer
only if all the steps in this section
have been followed. Ask your
dealer for advice and information
about towing a trailer with the
vehicle.
{Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.

Black plate (1,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-2
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-3
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-5
Engine Oil . . . . . . . . . . . . . . . . . . 10-10
Engine Oil Life System . . . . . 10-13
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-14
Engine Air Cleaner/Filter . . . . 10-17
Cooling System . . . . . . . . . . . . 10-19
Engine Coolant . . . . . . . . . . . . . 10-20
Engine Overheating . . . . . . . . 10-23
Overheated Engine Protection
Operating Mode . . . . . . . . . . . 10-25 Engine Fan . . . . . . . . . . . . . . . . . 10-25
Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . 10-26
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . 10-26
Washer Fluid . . . . . . . . . . . . . . . 10-27
Brakes . . . . . . . . . . . . . . . . . . . . . 10-28
Brake Fluid . . . . . . . . . . . . . . . . . 10-29
Battery . . . . . . . . . . . . . . . . . . . . . 10-30
Four-Wheel Drive . . . . . . . . . . . 10-31
Front Axle . . . . . . . . . . . . . . . . . . 10-32
Rear Axle . . . . . . . . . . . . . . . . . . 10-33
Noise Control System . . . . . . 10-34
Starter Switch Check . . . . . . . 10-35
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-35
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-35
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-36
Wiper Blade Replacement . . . . . . . . . . . . . . 10-36
Glass Replacement . . . . . . . . 10-37
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-37
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-37
Halogen Bulbs . . . . . . . . . . . . . . 10-37
LED Lighting . . . . . . . . . . . . . . . 10-37
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-38
Fog Lamps . . . . . . . . . . . . . . . . . 10-38
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-39
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-39
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-40
License Plate Lamp . . . . . . . . 10-40
Replacement Bulbs . . . . . . . . . 10-40
Electrical System
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-41
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-42
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-46
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-48

Black plate (6,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-6 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-88.
2. Battery on page 10-30.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-19.
4. Engine Air Cleaner/Filter on
page 10-17.
5. Automatic Transmission Dipstick (If Equipped). See “How to
Check Automatic Transmission
Fluid” under Automatic
Transmission Fluid on
page 10-14.
6. Remote Negative (–) Location. See Jump Starting on
page 10-88.
7. Engine Cooling Fans (Out of View). See Cooling System on
page 10-19.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-10. 9. Engine Oil Dipstick. See
“Checking Engine Oil” under
Engine Oil on page 10-10.
10. Brake Fluid Reservoir. See Brake Fluid on page 10-29.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-27.
12. Clutch Fluid Reservoir (If Equipped).
13. Engine Compartment Fuse
Block on page 10-42.

Black plate (8,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-8 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-88.
2. Battery on page 10-30.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-19.
4. Engine Air Cleaner/Filter on
page 10-17.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid on page 10-14.
6. Remote Negative (–) Location (Out of View). See Jump Starting
on page 10-88.
7. Engine Cooling Fans (Out of View). See Cooling System on
page 10-19.
8. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-10.
9. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-10. 10. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-27.
11. Brake Fluid Reservoir. See Brake Fluid on page 10-29.
12. Engine Compartment Fuse
Block on page 10-42.

Black plate (10,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-10 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-88.
2. Battery on page 10-30.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-19.
4. Engine Air Cleaner/Filter on
page 10-17.
5. Automatic Transmission Dipstick. See “How to Check
Automatic Transmission Fluid”
under Automatic Transmission
Fluid on page 10-14.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-10.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-10.
8. Engine Cooling Fan (Out of View). See Cooling System on
page 10-19.
9. Remote Negative (–) Location. See Jump Starting on
page 10-88. 10. Power Steering Fluid
Reservoir. See Power Steering
Fluid (1500 Series) on
page 10-26 orPower Steering
Fluid (2500/3500 Series) on
page 10-26.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-27.
12. Brake Fluid Reservoir. See Brake Fluid on page 10-29.
13. Auxiliary Battery (If Equipped). SeeBattery on page 10-30.
14. Engine Compartment Fuse
Block on page 10-42.
If the vehicle has a diesel engine
and/or an Allison Transmission, see
the Duramax diesel supplement.Engine Oil
For diesel engine vehicles, see
“Engine Oil” in the Duramax diesel
supplement.
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.Always use engine oil approved
to the proper specification and of
the proper viscosity grade. See
“Selecting the Right Engine Oil”
in this section.
.Check the engine oil level
regularly and maintain the
proper oil level. See “Checking
Engine Oil” and“When to Add
Engine Oil” in this section.
.Change the engine oil at the
appropriate time. See Engine Oil
Life System on page 10-13.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

Black plate (19,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-19
Warning (Continued)
cleaner not only cleans the air; it
helps to stop flames if the engine
backfires. Use caution when
working on the engine and do not
drive with the air cleaner/filter off.
{Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when you are driving.
Cooling System
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
The cooling system allows the
engine to maintain the correct
working temperature.
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
{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