2015 GMC SIERRA power steering

Black plate (1,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
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 . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . 10-11
Automatic Transmission Fluid (6 Speed
Transmission) . . . . . . . . . . . . . 10-12
Automatic Transmission Fluid (8 Speed
Transmission) . . . . . . . . . . . . . 10-15
Engine Air Cleaner/Filter . . . . 10-15
Cooling System . . . . . . . . . . . . 10-17
Engine Coolant . . . . . . . . . . . . . 10-18 Engine Overheating . . . . . . . . 10-21
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-23
Engine Fan . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . 10-24
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . 10-24
Washer Fluid . . . . . . . . . . . . . . . 10-25
Brakes . . . . . . . . . . . . . . . . . . . . . 10-26
Brake Fluid . . . . . . . . . . . . . . . . . 10-27
Battery . . . . . . . . . . . . . . . . . . . . . 10-29
Four-Wheel Drive . . . . . . . . . . . 10-29
Front Axle . . . . . . . . . . . . . . . . . . 10-30
Rear Axle . . . . . . . . . . . . . . . . . . 10-31
Noise Control System . . . . . . 10-32
Starter Switch Check . . . . . . . 10-33
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-34
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-34
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-34
Wiper Blade Replacement . . . . . . . . . . . . . . 10-35
Glass Replacement . . . . . . . . 10-35
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-36
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-36
Halogen Bulbs . . . . . . . . . . . . . . 10-36
LED Lighting . . . . . . . . . . . . . . . 10-36
Headlamps, Front Turn Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-36
Fog Lamps . . . . . . . . . . . . . . . . . 10-37
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-37
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-39
Replacement Bulbs . . . . . . . . . 10-40
Electrical System
Electrical System
Overload . . . . . . . . . . . . . . . . . . 10-40
Fuses . . . . . . . . . . . . . . . . . . . . . . 10-41
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-41
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . 10-45
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . 10-48

Black plate (8,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-8 Vehicle Care
1. Positive (+) Terminal. SeeJump
Starting on page 10-87.
2. Battery on page 10-29.
3. Coolant Surge Tank and Pressure Cap. See Cooling
System on page 10-17.
4. Engine Air Cleaner/Filter on
page 10-15.
5. Automatic Transmission Dipstick. See “How to Check the
Automatic Transmission Fluid”
under Automatic Transmission
Fluid (6 Speed Transmission) on
page 10-12 orAutomatic
Transmission Fluid (8 Speed
Transmission) on page 10-15.
6. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10-8.
7. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10-8.
8. Engine Cooling Fan (Out of View). See Cooling System on
page 10-17. 9. Remote Negative (–) Location.
See Jump Starting on
page 10-87.
10. Power Steering Fluid Reservoir. See Power Steering
Fluid (1500 Series) on
page 10-24 orPower Steering
Fluid (2500/3500 Series) on
page 10-24.
11. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid on
page 10-25.
12. Brake Fluid Reservoir. See Brake Fluid on page 10-27.
13. Auxiliary Battery (If Equipped). SeeBattery on page 10-29.
14. Engine Compartment Fuse
Block on page 10-41.
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 10-11.
.Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.

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 (25,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-25
SeeEngine Compartment Overview
on page 10-5 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
Wait for the power steering system
to cool, with the engine off, before
checking the fluid.
How to Check Power Steering
Fluid
To check the power steering fluid:
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag. 4. Replace the cap and completely
tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.
The level should be between the
ADD and FULL marks. If necessary,
add only enough fluid to bring the
level up to the hashed area between
the ADD and FULL marks.
What to Use
To determine what kind of fluid to
use, see Recommended Fluids and
Lubricants on page 11-12. Always
use the proper fluid.
{Caution
Use of the incorrect fluid may
damage the vehicle and the
damages may not be covered by
the vehicle warranty. Always use
the correct fluid listed in
Recommended Fluids and
Lubricants on page 11-12.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes on
when the washer fluid is low. The
message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.

Black plate (47,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-47
Number Usage12 Accessory Power Outlet 1/Cigarette
Lighter
13 Discrete Logic Ignition Switch
14 Switch Backlighting
17 Body Control Module 1
19 Spare
20 Spare
22 Heater, Ventilation, and Air Conditioning/
Auxiliary Heater,
Ventilation and Air
Conditioning Ignition
23 Instrument Cluster Ignition/Sensing
Diagnostic Module
Ignition
24 Spare
25 Data Link Connector/ Driver Seat Module Number Usage
26 Passive Entry Passive Start/Heater,
Ventilation, and Air
Conditioning
27 Spare
28 Spare
29 Park Enable/ Electrically Adjustable
Pedals
30 SEO
31 Accessory/Run Crank
32 Heated Steering Wheel
33 Spare
34 Instrument Cluster
36 Spare
37 Spare
40 Left Doors
41 Driver Power Seat Number Usage
43 Left Front Heated/ Cooled Seat
44 Right Front Heated/ Cooled Seats
45 Spare
49 Retained Accessory Power/Accessory
50 Run/Crank

Black plate (49,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
Vehicle Care 10-49
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Number Usage
1 Accessory Power Outlet 3
2 Accessory Power Outlet 4
7 Body Control Module 4
8 Body Control Module 8
9 Rear Seat Entertainment
10 Cargo Lamp
15 Steering Wheel Controls
18 Radio
19 Spare
20 Sunroof
23 Airbag/Info Number Usage
26 Export/Power Take Off/SEO Battery 1
27 Obstacle Detection/ USB Ports
28 Body Control Module 2
32 SEO Battery 2
35 AC Inverter
36 Amplifier
37 Spare
39 Rear Sliding Window
42 Right Door Window Motor
43 Front Blower
44 SEO
45 Body Control Module 6
46 Body Control Module 7
47 Passenger Seat Number Usage
50 Retained Accessory Power/Accessory
51 Rear Sliding Window Open
52 Rear Sliding Window Close

Black plate (100,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
10-100 Vehicle Care
Tires
Use a stiff brush with tire cleaner to
clean the tires.
{Caution
Using petroleum-based tire
dressing products on the vehicle
may damage the paint finish and/
or tires. When applying a tire
dressing, always wipe off any
overspray from all painted
surfaces on the vehicle.
Wheels and Trim—Aluminum
or Chrome
Use a soft, clean cloth with mild
soap and water to clean the wheels.
After rinsing thoroughly with clean
water, dry with a soft, clean towel.
A wax may then be applied.
{Caution
Chrome wheels and other chrome
trim may be damaged if the
vehicle is not washed after driving
on roads that have been sprayed
with magnesium, calcium,
or sodium chloride. These
chlorides are used on roads for
conditions such as ice and dust.
Always wash the chrome with
soap and water after exposure.
{Caution
To avoid surface damage, do not
use strong soaps, chemicals,
abrasive polishes, cleaners,
brushes, or cleaners that contain
acid on aluminum or
chrome-plated wheels. Use only
approved cleaners. Also, never
drive a vehicle with aluminum or
chrome-plated wheels through an
(Continued)
Caution (Continued)
automatic car wash that uses
silicone carbide tire cleaning
brushes. Damage could occur
and the repairs would not be
covered by the vehicle warranty.
Steering, Suspension, and
Chassis Components
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of wear at
least once a year.
Inspect power steering for proper
hook-up, binding, leaks, cracks,
chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
1500 Series vehicles, at least every
other oil change lubricate the outer
tie rod ends.

Black plate (12,1)GMC 2015i Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8431500) - 2015 - crc - 6/20/14
11-12 Service and Maintenance
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
This maintenance section applies to vehicles with a gasoline engine. If the vehicle has a diesel engine and/or an
Allison Transmission, see the maintenance schedule section in the Duramax diesel supplement.
Fluids and lubricants identified below by name, part number, or specification can be obtained from your dealer.Usage Fluid/Lubricant
Engine Oil Use only engine oil licensed to the dexos1
®specification of the proper SAE
viscosity grade. ACDelco dexos1 Synthetic Blend is recommended. See
Engine Oil on page 10-8.
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL
®coolant.
See Engine Coolant on page 10-18.
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 19299818, in Canada 19299819).
Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.
Hydraulic Power Steering System (HD Only) GM Power Steering Fluid (GM Part No. 89021185, in Canada 89021186).
Automatic Transmission (All except 6.2L with 8-Speed transmission) DEXRON
®-VI Automatic Transmission Fluid.