service CHEVROLET SILVERADO 1500 2015 Repair Manual

Black plate (48,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
9-48 Driving and Operating
indicator, turn the knob to another
position so that it matches the
actual transfer case setting. If no
lights display, take the vehicle to
your dealer for service. An indicator
light flashes while shifting the
transfer case and remains
illuminated when the shift is
complete.
If the transfer case cannot make a
requested shift, it will return to the
last chosen setting. Turn the knob
back to the previous transfer case
setting to see the indicator.
The settings are:
N (Neutral):Use only when the
vehicle needs to be towed. See
Recreational Vehicle Towing on
page 10-95 orTowing the Vehicle
on page 10-95.
2
m(Two-Wheel Drive High): Use
for driving on most streets and
highways. The front axle is not
engaged. This setting provides the
best fuel economy. AUTO (Automatic Four-Wheel
Drive):
Use when road surface
traction conditions are variable.
When driving in AUTO, the front
axle is engaged, and the vehicle's
power is sent to the front and rear
wheels automatically based on
driving conditions. This setting
provides slightly lower fuel economy
than 2
m.
Do not use AUTO mode to park on
a steep grade with poor traction
such as ice, snow, mud, or gravel.
In AUTO mode only the rear wheels
will hold the vehicle from sliding
when parked. If parking on a steep
grade, use 4
mto keep all four
wheels engaged.
4
m(Four-Wheel Drive High): Use
this position when extra traction is
needed, such as when driving on
snowy or icy roads, when
off-roading, or when plowing snow.
4
n(Four-Wheel Drive Low): This
setting engages the front axle and
delivers extra torque. Choose 4
n
when driving off-road in deep sand,
deep mud, or deep snow, and while
climbing or descending steep hills.
Shifting into 4
nwill turn Traction
Control and StabiliTrak off. See
Traction Control/Electronic Stability
Control on page 9-54.
Shifting Into 4
mor AUTO
Turn the knob to the 4
mor AUTO
position at any speed, except from
4
n. The indicator light will flash
while shifting and will remain on
when the shift is completed.
Shifting Into 2
m
Turn the knob to 2mat any speed,
except when shifting from 4
n. The
indicator light will flash while shifting
and will remain on when the shift is
completed.
Shifting Into 4
n
When 4nis engaged, keep vehicle
speed below 72 km/h (45 mph).

Black plate (66,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
9-66 Driving and Operating
Consider traffic and weather
conditions when selecting the alert
timing. The range of selectable alert
timing may not be appropriate for all
drivers and driving conditions.
Unnecessary Alerts
FCA may provide unnecessary
alerts for turning vehicles, vehicles
in other lanes, objects that are not
vehicles, or shadows. These alerts
are normal operation and the
vehicle does not need service.
Cleaning the System
If the FCA system does not seem to
operate properly, cleaning the
outside of the windshield in front of
the rearview mirror, and cleaning the
front of the vehicle where radar
sensors are located, may correct
the issue.
Lane Departure
Warning (LDW)
If equipped, LDW may help avoid
crashes due to unintentional lane
departures. It may provide an alert if
the vehicle is crossing a lane
marking without using a turn signal
in that direction. LDW uses a
camera sensor to detect the lane
markings at speeds of 56 km/h
(35 mph) or greater.
{Warning
The LDW system does not steer
the vehicle. The LDW system
may not:
.Provide enough time to avoid
a crash.
.Detect lane markings under
poor weather or visibility
conditions. This can occur if
the windshield or headlamps
are blocked by dirt, snow,
or ice; if they are not in(Continued)
Warning (Continued)
proper condition; or if the sun
shines directly into the
camera.
.Detect road edges.
.Detect lanes on winding or
hilly roads.
If LDW only detects lane
markings on one side of the road,
it will only warn you when
departing the lane on the side
where it has detected a lane
marking. Always keep your
attention on the road and
maintain proper vehicle position
within the lane, or vehicle
damage, injury, or death could
occur. Always keep the
windshield, headlamps, and
camera sensors clean and in
good repair. Do not use LDW in
bad weather conditions.

Black plate (67,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Driving and Operating 9-67
How the System Works
The LDW camera sensor is on the
windshield ahead of the rearview
mirror.
To turn LDW on and off, press
@on
the center stack. The control
indicator will light when LDW is on.
When LDW is on,@is green if
LDW is available to warn of a lane
departure. If the vehicle crosses a
detected lane marking without using
the turn signal in that direction,
@
changes to amber and flashes.
Additionally, there will be three
beeps, or the driver seat will pulse
three times on the right or left,
depending on the lane departure
direction.
When the System Does Not
Seem to Work Properly
The system may not detect lanes as
well when there are:
.Close vehicles ahead.
.Sudden lighting changes, such
as when driving through tunnels.
.Banked roads.
If the LDW system is not functioning
properly when lane markings are
clearly visible, cleaning the
windshield may help.
LDW alerts may occur due to tar
marks, shadows, cracks in the road,
temporary or construction lane
markings, or other road
imperfections. This is normal system
operation; the vehicle does not need
service. Turn LDW off if these
conditions continue.
Fuel
For diesel engine vehicles, see
“Fuel for Diesel Engines” in the
Duramax diesel supplement.
Use of the recommended fuel is an
important part of the proper
maintenance of this vehicle. When
driving in the U.S. and Canada, to
help keep the engine clean and
maintain optimum vehicle
performance, we recommend using
TOP TIER Detergent Gasolines.
See www.toptiergas.com for a list of
TOP TIER Detergent Gasolines.

Black plate (68,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
9-68 Driving and Operating
If the vehicle has a yellow fuel cap,
E85 or FlexFuel can be used in the
vehicle. SeeE85 or FlexFuel on
page 9-69.
For all vehicles except those with
the 6.2L V8 engine, use regular
unleaded gasoline meeting ASTM
specification D4814 with a posted
octane rating of 87 or higher. Do not
use gasoline with an octane rating
below 87, as it may cause engine
damage and will lower fuel
economy.
If the vehicle has the 6.2L V8 engine
(VIN Code J), use premium
unleaded gasoline meeting ASTM
specification D4814 with a posted
octane rating of 91 or higher.
Regular unleaded gasoline rated at
87 octane or higher can be used,
but acceleration and fuel economy
will be reduced, and an audible
knocking noise may be heard. If this
occurs, use a gasoline rated at
91 octane or higher as soon as
possible. Otherwise, the engine
could be damaged. If heavy knocking is heard when using
gasoline with a 91 octane rating or
higher, the engine needs service.
Use of Seasonal Fuels
Use summer and winter fuels in the
appropriate season. The fuels
industry automatically modifies the
fuel for the appropriate season.
If fuel is left in the vehicle tank for
long periods of time, driving or
starting could be affected. Drive the
vehicle until the fuel is at one-half
tank or less, then refuel with the
current seasonal fuel.
Prohibited Fuels
Gasolines containing oxygenates
such as ethers and ethanol, as well
as reformulated gasolines, are
available in some cities. If these
gasolines comply with the
previously described specification,
then they are acceptable to use.
However, E85 (85% ethanol) and
other fuels containing more than
15% ethanol must be used only in
FlexFuel vehicles.{Caution
Do not use fuel containing
methanol. It can corrode metal
parts in the fuel system and also
damage plastic and rubber parts.
That damage would not be
covered under the vehicle
warranty.
Some gasolines, mainly high octane
racing gasolines, can contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). Do not use
gasolines and/or fuel additives with
MMT as they can reduce spark plug
life and affect emission control
system performance. The
malfunction indicator lamp may turn
on. If this occurs, see your dealer
for service.

Black plate (75,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Driving and Operating 9-75
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.
SeeTow/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 10-25.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.
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

Black plate (94,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
9-94 Driving and Operating
The harness contains the following
camper/trailer circuits:
.Green/Violet: Left Stop/Turn
Signal
.Yellow/Gray: Right Stop/Turn
Signal
.Gray/Brown: Taillamps/Parking
Lamps
.White: Ground
.White/Green: Back-up Lamps
.Red/Green: Battery Feed
.Dark Blue: Trailer Brake
If the vehicle is equipped with the
heavy-duty trailering option, see
“Heavy-Duty Trailer Wiring Harness
Package” earlier in this section. When the camper-wiring harness is
ordered without the heavy-duty
trailering package, a seven-wire
harness with a seven-pin connector
is at the rear of the vehicle and is
tied to the vehicle's frame.
Electric Brake Control Wiring
Provisions
These wiring provisions are
included with the vehicle as part of
the trailer wiring package. These
provisions are for an electric brake
controller.
The harness should be installed by
your dealer or a qualified service
center.
Tow/Haul Mode
Pressing this button at the end of
the shift lever turns on and off the
Tow/Haul Mode.

Black plate (97,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Driving and Operating 9-97
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).
.A trailer with electric brakes has
become disconnected (a
CHECK TRAILER WIRING
message will also display on
the DIC).
.There is a fault present in the
wiring to the trailer brakes (a
CHECK TRAILER WIRING
message will also display on
the DIC).
.The ITBC system is not working
due to a fault (a SERVICE
TRAILER BRAKE SYSTEM
message will also display in
the DIC).
Manual Trailer Brake Apply
The Manual Trailer Brake Apply
Lever is used to apply the trailer ’s
electric brakes independent of the
vehicle’s brakes. Sliding the lever to
the left will apply only the trailer
brakes. Use this lever to adjust
Trailer Gain to properly adjust the
power output to the trailer brakes.

Black plate (99,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Driving and Operating 9-99
CHECK TRAILER WIRING: This
message will display if:
.The ITBC system first
determines connection to a
trailer with electric brakes and
then the trailer harness becomes
disconnected from the vehicle.
If the disconnect occurs while
the vehicle is stationary, this
message will automatically turn
off in about 30 seconds. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while
the vehicle is moving, this
message will continue until the
ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer
harness is reconnected.
.There is an electrical fault in the
wiring to the trailer brakes. This
message will continue as long
as there is an electrical fault inthe trailer wiring. This message
will also turn off if it is
acknowledged.
To determine if the electrical fault is
on the vehicle side or trailer side of
the trailer wiring harness
connection:
1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition off.
3. Wait 10 seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the
electrical fault is on the
vehicle side.
If the CHECK TRAILER WIRING
message only reappears when
connecting the trailer wiring
harness to the vehicle, the
electrical fault is on the
trailer side.
SERVICE TRAILER BRAKE
SYSTEM: This message will display
when there is a problem with the
ITBC system. If this message continues over multiple ignition
cycles, there is a problem with the
ITBC system. Have the vehicle
serviced.
If either the CHECK TRAILER
WIRING or SERVICE TRAILER
BRAKE SYSTEM message displays
while driving, the ITBC system may
not be fully functional or may not
function at all. When traffic
conditions allow, carefully pull the
vehicle over to the side of the road
and turn the ignition off. Check the
wiring connection to the trailer and
turn the ignition back on. If either of
these messages continues, either
the vehicle or trailer needs service.
A GM dealer may be able to
diagnose and repair problems with
the trailer. However, any diagnosis
and repair of the trailer is not
covered under the vehicle warranty.
Contact your trailer dealer for
assistance with trailer repairs and
trailer warranty information.

Black plate (1,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-3
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-5
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Oil . . . . . . . . . . . . . . . . . . 10-11
Engine Oil Life System . . . . . 10-14
Automatic Transmission Fluid (6 Speed
Transmission) . . . . . . . . . . . . . 10-15
Automatic Transmission Fluid (8 Speed
Transmission) . . . . . . . . . . . . . 10-18
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-19 Hydraulic Clutch . . . . . . . . . . . . 10-19
Engine Air Cleaner/Filter . . . . 10-19
Cooling System . . . . . . . . . . . . 10-21
Engine Coolant . . . . . . . . . . . . . 10-22
Engine Overheating . . . . . . . . 10-25
Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-27
Engine Fan . . . . . . . . . . . . . . . . . 10-27
Power Steering Fluid (1500 Series) . . . . . . . . . . . . . 10-28
Power Steering Fluid (2500/3500 Series) . . . . . . . . 10-28
Washer Fluid . . . . . . . . . . . . . . . 10-29
Brakes . . . . . . . . . . . . . . . . . . . . . 10-30
Brake Fluid . . . . . . . . . . . . . . . . . 10-31
Battery . . . . . . . . . . . . . . . . . . . . . 10-32
Four-Wheel Drive . . . . . . . . . . . 10-33
Front Axle . . . . . . . . . . . . . . . . . . 10-34
Rear Axle . . . . . . . . . . . . . . . . . . 10-35
Noise Control System . . . . . . 10-36
Starter Switch Check . . . . . . . 10-37
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . 10-37
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-38 Park Brake and P (Park)
Mechanism Check . . . . . . . . 10-38
Wiper Blade Replacement . . . . . . . . . . . . . . 10-38
Glass Replacement . . . . . . . . 10-39
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-39
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-40
Halogen Bulbs . . . . . . . . . . . . . . 10-40
Headlamps, Front Turn
Signal, Sidemarker, and
Parking Lamps . . . . . . . . . . . . 10-40
Fog Lamps . . . . . . . . . . . . . . . . . 10-41
Taillamps (Chassis Cab Models) . . . . . . . . . . . . . . . . . . . 10-41
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . 10-41
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . 10-43
Replacement Bulbs . . . . . . . . . 10-43

Black plate (3,1)Chevrolet 2015i Silverado Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-8425172) - 2015 - CRC - 6/20/14
Vehicle Care 10-3
General Information
For service and parts needs, visit
your dealer. You will receive
genuine GM parts and GM-trained
and supported service people.
Genuine GM parts have one of
these marks:
California Proposition
65 Warning
Most motor vehicles, including this
one, contain and/or emit chemicals
known to the State of California tocause cancer and birth defects or
other reproductive harm. Engine
exhaust, many parts and systems,
many fluids, and some component
wear by-products contain and/or
emit these chemicals.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag
initiators, safety belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non‐dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride andhandling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non‐GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle on
page 3-34.