2015 GMC SIERRA 1500 power steering

Black plate (93,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Driving and Operating 9-93
Trailer Brake Control Panel
1. Manual Trailer Brake ApplyLever
2. Trailer Gain Adjustment Buttons
The ITBC system has a control
panel on the instrument panel to the
left of the steering column. See
Instrument Panel on page 1-2. The
control panel allows adjustment to
the amount of output, referred to as
Trailer Gain, available to the trailer
brakes and allows manual
application of the trailer brakes. The
Trailer Brake Control Panel is used along with the Trailer Brake Display
Page on the Driver Information
Center (DIC) to adjust and display
power output to the trailer brakes.
Trailer Brake DIC Display Page
The ITBC system displays
messages in the DIC.
The display page indicates Trailer
Gain setting, power output to the
trailer brakes, trailer connection, and
system operational status.
To display the Trailer Brake Display
Page, do any of the following:.Scroll through the DIC menu
pages.
.Press a Trailer Gain button.
If the Trailer Brake Display Page
is not currently displayed, press
a Trailer Gain button to recall the
current Trailer Gain setting.
Each press and release of the
gain buttons will then change the
Trailer Gain setting.
.Activate the Manual Trailer
Brake Apply Lever.
TRAILER GAIN: This setting can be
adjusted from 0.0 to 10.0 with either
a trailer connected or disconnected.
To adjust the Trailer Gain, press one
of the Trailer Gain Adjustment
buttons. Press and hold a gain
button to continuously adjust the
Trailer Gain. To turn the output to
the trailer off, adjust the Trailer Gain
setting to 0.0 (zero).
TRAILER OUTPUT: This displays
anytime a trailer with electric brakes
is connected. Output to the trailer
brakes is based on the amount of
vehicle braking present and relative
to the Trailer Gain setting. Output is
displayed from 0 to 100% for each
gain setting.
The Trailer Output will indicate
“- - -
- - -” on the Trailer Brake Display
Page whenever the following occur:
.No trailer is connected.
.A trailer without electric brakes
is connected (no DIC message
will display).

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 (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 (26,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-26 Vehicle Care
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 normal
and indicates that the cooling
system is functioning properly. Thefans 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)
See
Engine 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.

Black plate (47,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Vehicle Care 10-47
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Number Usage
1 Accessory Power Outlet 2
2 SEO Retained Accessory Power
3 Universal Garage Door Opener/Inside
Rearview Mirror
6 Body Control Module 3
7 Body Control Module 5
8 Driver Window Switch/Mirror Switch
9 Spare
10 Accessory Power Outlet Retained
Accessory Power
11 Accessory Power Outlet Battery Number Usage
12 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

Black plate (49,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
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

Black plate (102,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
10-102 Vehicle Care
{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
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.
2500/3500 Series vehicles, at least
every other engine oil change
lubricate the upper and lower
control arm ball joints. Control arm
ball joints on 1500 series vehicles
are maintenance-free.
2500/3500 Series vehicles equipped
with steering linkage, at least every
other engine oil change lubricate the
tie rod ball joints, idler arm pivot
shaft bearings, idler arm socket, and
pitman arm socket.
{Caution
Lubrication of applicable Steering/
Suspension points should not be
done unless temperature is -12°C
(10°F) or higher, or damage could
result.
Body Component Lubrication
Lubricate all key lock cylinders,
hood hinges, liftgate hinges, and the
steel fuel door hinge unless the
components are plastic. Applying
silicone grease on weatherstrips
with a clean cloth will make them
last longer, seal better, and not stick
or squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush dirt and
debris from the vehicle's underbody.
Your dealer or an underbody car
washing system can do this. If not
removed, rust and corrosion can
develop.

Black plate (12,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
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 10-10.
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL coolant. SeeEngine Coolant on page 10-20.
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 DEXRON
®-VI Automatic Transmission Fluid.
Key Lock Cylinders Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in Canada 10953474).