Page 409 of 544

Black plate (35,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
Vehicle Care 10-35
fill plug hole, located on the rear
axle. Add only enough fluid to
reach the proper level.
.For all 6.0L 2500HD Series
applications, the proper level is
from 0 mm to 13 mm (0 to 0.5 in)
below the bottom of the fill plug
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
.For all 6.6L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer toRecommended Fluids and
Lubricants on page 11-12 to
determine what kind of lubricant
to use.
Noise Control System
The following information relates to
compliance with federal noise
emission standards for vehicles with
a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lb). The noise control
system warranty is given in your
warranty manual.
These standards apply only to
vehicles sold in the United States.
Federal law prohibits the following
acts or the causing thereof:
1. The removal or rendering inoperative by any person, other
than for purposes of
maintenance, repair or
replacement, of any device or
element of design incorporated
into any new vehicle for the
purpose of noise control, prior to
its sale or delivery to the ultimate
purchaser or while it is in use; or 2. The use of the vehicle after such
device or element of design has
been removed or rendered
inoperative by any person.
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Page 410 of 544

Black plate (36,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
10-36 Vehicle Care
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner.
Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. 2. Apply both the parking brake
and the regular brake.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{Warning
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured. 1. Before starting this check, be
sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Apply the parking brake. Be ready to apply the regular brake
immediately if the vehicle begins
to move.
3. With the engine off, turn the ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Page 411 of 544

Black plate (37,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
Vehicle Care 10-37
Ignition Transmission
Lock Check
If equipped with a key type ignition,
while parked and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the shift
lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift to
P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear or cracking. See
Maintenance Schedule on
page 11-3.
Replacement blades come in
different types and are removed in
different ways. For proper
windshield wiper blade length and
type, see Maintenance
Replacement Parts on page 11-14.
Page 412 of 544

Black plate (38,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
10-38 Vehicle Care
{Caution
Allowing the wiper arm to touch
the windshield when no wiper
blade is installed could damage
the windshield. Any damage that
occurs would not be covered by
your warranty. Do not allow the
wiper arm to touch the windshield.
To replace the windshield wiper
blade:
1. Pull the windshield wiper assembly away from the
windshield.
2. Press the button (2) in themiddle of the wiper arm
connector, and pull the wiper
blade away from the arm
connector (1).
3. Remove the wiper blade.
4. Reverse Steps 1–3 for wiper blade replacement.
Glass Replacement
If the windshield or front side glass
must be replaced, see your dealer
to determine the correct
replacement glass.
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Page 413 of 544

Black plate (39,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
Vehicle Care 10-39
Bulb Replacement
For the proper type of replacement
bulbs, seeReplacement Bulbs on
page 10-42.
For any bulb‐changing procedure
not listed in this section, contact
your dealer.
Halogen Bulbs
{Warning
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps
Driver Side
1. Front Turn Signal/Sidemarker/
Parking Lamp
2. High/Low-Beam Headlamp
See your dealer for passenger side
replacement.
Headlamp
1. Open the hood.
2. Remove the headlamp bulb assembly cover by turning it
counterclockwise.
3. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly
and pull it straight out.
4. Unplug the electrical connector from the old bulb by releasing
the clip on the bulb socket.
Turn Signal/Sidemarker/
Parking Lamp
1. Open the hood.
2. If replacing a bulb on the
passenger side, remove the
engine air cleaner.
3. Turn the bulb socket counterclockwise to remove it
from the headlamp assembly
and pull it straight out.
4. Remove the bulb by pulling it straight out of the bulb socket.
Page 414 of 544
Black plate (40,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
10-40 Vehicle Care
Fog Lamps
To replace the front fog lamp bulb:
1. Locate the fog lamp under thefront bumper.
2. Disconnect the electrical connector from the fog lamp bulb
assembly by pressing the
connector release.
3. Remove the bulb from the housing by squeezing the two
release tabs and pulling it
straight out of the assembly.
Taillamps (Chassis Cab
Models)
1. Back-Up Lamp
2. Stoplamp/Taillamp/TurnSignal Lamp
To replace one of these bulbs:
1. Remove the four screws.
2. Lift the lens off the lamp assembly.
3. Turn the old bulb counterclockwise and pull it
straight out from the socket.
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps
Single Rear Wheel Lamp Shown,
Dual Rear Wheel Lamp Similar
1. Stoplamp/Taillamp/Turn Signal Lamp
2. Back-Up Lamp
3. Sidemarker Lamp
Page 415 of 544
Black plate (41,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
Vehicle Care 10-41
To replace one of these bulbs:
1. Open the tailgate.
2. Remove the two rear lampassembly screws and pull
rearward until disengaging the
two outer pins on the taillamp
assembly from the vehicle.
3. Turn the bulb socket counterclockwise to remove it
from the taillamp assembly.
4. Pull the bulb straight out from the socket.
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp
1. Cargo Lamps
2. Center High-Mounted Stoplamp
(CHMSL) Bulb To replace one of these bulbs:
1. Remove the two screws and lift
off the lamp assembly.
2. Turn the bulb socket counterclockwise and pull it
straight out.
3. Pull the bulb straight out from the socket.
Page 416 of 544

Black plate (42,1)GMC Sierra Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
5853626) - 2014 - 3rd crc - 6/6/14
10-42 Vehicle Care
License Plate Lamp
To replace one of these bulbs:
1. Locate the license plate lampunder the rear bumper.
2. Turn the bulb socket counterclockwise and pull it
straight out.
3. Pull the bulb straight out of the socket.
Replacement Bulbs
Exterior Lamp Bulb Number
Back-Up Lamp 921 (W16W)
Back-Up Lamp* 1156
Cargo Lamp 921 (W16W)
Center
High-Mounted
Stoplamp
(CHMSL) 921LL
Fog Lamp PS24WExterior Lamp Bulb
Number
Front Turn Signal
Lamp and
Parking Lamp 7443 LL
High/Low-Beam
Headlamp HIR–2
(9012 LL)
License
Plate Lamp W5W LL
Rear
Sidemarker Lamp 194
Stoplamp/Taillamp/
Turn Signal Lamp 7444 LL
Stoplamp/Turn
Signal Lamp/
Taillamp* 1157
* Chassis Cab Models
For replacement bulbs not listed
here, contact your dealer.
Electrical System
Electrical System
Overload
The vehicle has fuses to protect
against an electrical system
overload. Fuses also protect power
devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, there
are some spare fuses and a fuse
puller in the Instrument Panel Fuse
Block. The same amperage fuse
can also be borrowed. Choose
some feature of the vehicle that is
not needed to use and replace it as
soon as possible.
Headlamp Wiring
An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the