GMC Duramax Diesel 2015 User manual

2k15_misc_duramax_diesel_22948873B.ai
(Modern Bridge - Level 2 / #23321109)
Spine = Saddle Stitch
Color = Black
Date = 03/28/14
22948873 B

Black plate (1,1)
Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
7132827) - 2015 - CRC - 10/21/14
2015 Chevrolet/GMC Duramax Diesel Supplement M
In Brief ........................ 1-1
Initial Drive Information . . . . . . . . 1-1
Performance and
Maintenance . . . . . . . . . . . . . . . . . 1-2
Instruments and Controls . . . . 5-1
Warning Lights, Gauges, and
Indicators . . . . . . . . . . . . . . . . . . . . 5-2
Information Displays . . . . . . . . . . 5-11
Vehicle Messages . . . . . . . . . . . . 5-12
Vehicle Personalization . . . . . . . 5-16
Driving and Operating . . . . . . . . 9-1
Starting and Operating . . . . . . . . . 9-1
Diesel Particulate Filter . . . . . . . 9-12
Diesel Exhaust Fluid . . . . . . . . . 9-13
Brakes . . . . . . . . . . . . . . . . . . . . . . . 9-20
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 9-21
Towing . . . . . . . . . . . . . . . . . . . . . . . 9-38
Conversions and Add-Ons . . . 9-43
Vehicle Care . . . . . . . . . . . . . . . . . 10-1
General Information . . . . . . . . . . 10-1
Vehicle Checks . . . . . . . . . . . . . . . 10-3
Service and Maintenance . . . 11-1
General Information . . . . . . . . . . 11-1
Maintenance Schedule . . . . . . . 11-3
Special Application
Services . . . . . . . . . . . . . . . . . . . . 11-7
Recommended Fluids . . . . . . . . 11-8
Maintenance Records . . . . . . . 11-12
Technical Data . . . . . . . . . . . . . . . 12-1
Vehicle Data . . . . . . . . . . . . . . . . . . 12-2
Index ..................... i-1

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Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
7132827) - 2015 - CRC - 10/21/14
ii Introduction
The names, logos, emblems,
slogans, vehicle model names, and
vehicle body designs appearing in
this manual including, but not limited
to, GM, the GM logo, CHEVROLET,
GMC, the CHEVROLET and GMC
Truck Emblems, SILVERADO,
SIERRA, DENALI, EXPRESS,
SAVANA, and Duramax are
trademarks and/or service marks of
General Motors LLC, its
subsidiaries, affiliates, or licensors.
For vehicles first sold in Canada,
substitute the name “General
Motors of Canada Limited”for GMC
and Chevrolet Motor Division
wherever it appears in this manual.
This manual describes features that
may or may not be on the vehicle
because of optional equipment that
was not purchased on the vehicle,
model variants, country
specifications, features/applications
that may not be available in your
region, or changes subsequent to
the printing of this owner manual.
Refer to the purchase
documentation relating to your
specific vehicle to confirm the
features.
This manual contains information
that pertains to the operation of your
diesel engine. It also contains your
Diesel Maintenance Schedule. The
sections in this manual correspond
to the sections in your owner
manual. This manual, along with
your owner manual, will assist you
in the proper use and maintenance
of your vehicle.
Keep this manual in the vehicle for
quick reference.
Canadian Vehicle Owners
Propriétaires Canadiens
A French language manual can be
obtained from your dealer, at
www.helminc.com, or from:
On peut obtenir un exemplaire de
ce guide en français auprès du
concessionnaire ou à l'adresse
savant:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Litho in U.S.A.
Part No. 22948873 C Third Printing ©2014 General Motors LLC. All Rights Reserved.

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Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
7132827) - 2015 - CRC - 10/21/14
Introduction iii
Using this Supplement
This supplement contains
information specific to the unique
components of the vehicle. It does
not explain everything you need to
know about the vehicle. Read this
supplement along with the owner
manual to learn about the vehicle's
features and controls.
Index
A good place to look for what you
need is the Index in back of this
supplement. It is an alphabetical list
of what is in the supplement, and
the page number where you will
find it.

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iv Introduction
2NOTES

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Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
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In Brief 1-1
In Brief
Initial Drive Information
Transmission . . . . . . . . . . . . . . . . . . 1-1
Performance and Maintenance
Engine Oil Life System . . . . . . . . 1-2
Diesel Particulate Filter . . . . . . . 1-2
Diesel Exhaust Fluid . . . . . . . . . . 1-3
Initial Drive
Information
Transmission
Pickup Models
Cold Operation
When temperatures are very cold,
the transmission will prevent certain
operations to protect against
damage. The information below
shows shift range availability based
on transmission oil temperature:
.All shift ranges available at
−25°C (−13°F) or above.
.2 (Second) and 3 (Third) shift
ranges only at −35°C (−31°F) to
−25°C (−13°F).
.2 (Second) shift range only at
−35°C (−31°F) or lower.
Torque converter clutch operation
will also be prevented when air or
transmission oil temperatures are
below certain levels.
For areas where ambient
temperatures are below −40°C
(−40°F), use synthetic transmission
fluid approved to Allison
Transmission
®
specification
TES-295. See Recommended
Fluids and Lubricants on page 11-8
and Automatic Transmission Fluid
on page 10-9.
Adaptive Shift Controls
The shift quality of a new vehicle
may not be ideal because the
Adaptive Shift Control process may
not have determined the best
settings for a particular shift or
condition. Shift quality will improve
with continued driving.
Low Traction Mode
Low Traction Mode aids in vehicle
acceleration on slippery road
surfaces such as ice or snow. By
selecting 2 (Second) using Range
Selection Mode while at a stop, the
transmission will limit torque to the
drive wheels to prevent slippage.

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1-2 In Brief
Heater Performance Mode
When cold weather conditions are
detected, the transmission raises
part throttle upshift points after the
1 (First) to 2 (Second) upshift to
increase engine speed. This feature
shortens engine and cab warm up
times.
When the transmission is in this
mode, upshifts may be delayed.
This is normal and does not indicate
an operational problem.
Four-Wheel Drive
When operating in 4 ↓
(Four-Wheel-Drive Low), there is a
very deep gear reduction. The
resulting shifts will feel exaggerated.
Performance and
Maintenance
Engine Oil Life System
The engine oil life system calculates
engine oil life based on vehicle use
and displays the CHANGE ENGINE
OIL SOON message when it is time
to change the engine oil and filter.
The oil life system should be reset
to 100% only following an oil
change. See “Engine Oil Life
System”in the owner manual.
Diesel Particulate Filter
The Duramax engine is equipped
with a Diesel Particulate Filter (DPF)
that, by design, will filter or trap
particulates. The DPF is located
under the vehicle in the exhaust
system.
Depending on a number of factors
monitored by the engine computer,
the DPF will need to be cleaned of
accumulated solids. When a
cleaning is needed, the engine
computer will initiate a cleaning
action by warming the exhaust gas
temperature. This feature has been
designed to operate automatically,
with limited operator involvement or
awareness.
Cleaning the DPF (Exhaust
Filter)
While the DPF cleaning is
automatically controlled by the
engine computer, the vehicle will
need to operate continuously until
the message is no longer displayed.
See Diesel Particulate Filter
Messages on page 5-14. Cleaning
occurs most effectively above
48 km/h (30 mph). If the vehicle is
returned to idle during the cleaning
process, the driver may notice a
slightly different sound or a slightly
elevated engine idle speed. This is
normal. No action is required on the
part of the driver during a regular
DPF cleaning. See Diesel
Particulate Filter on page 9-12.

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In Brief 1-3
Special DPF Driver Messages
If the vehicle is used for numerous
short trips or extended slow-speed
operation, the engine computer may
not be able to adequately heat up
the exhaust system to clean the
DPF effectively. The engine
computer has been designed to
continuously monitor the condition
of the DPF. When the engine
computer detects that the DPF is
nearly full of particulates and that
the vehicle is not being operated in
a manner that would allow effective
automatic DPF cleaning, the Driver
Information Center will display a
message. See Diesel Particulate
Filter Messages on page 5-14.
If the vehicle continues to be driven
in a manner that prevents effective
DPF cleaning, the DPF will become
plugged with particulates. If this
occurs, the engine computer will
turn on the service engine soon light
in the instrument cluster and the
DIC will display the message
ENGINE POWER IS REDUCED.
See Diesel Particulate Filter on
page 9-12 and Engine Power
Messages on page 5-13.
Fuel
Use Ultra Low Sulfur Diesel
Fuel (ULSD)
Use ULSD only. The emission
control hardware used on the
vehicle may be damaged by using
fuel with high sulfur levels. Use only
fuel that is dispensed from pumps
bearing the ULSD label.
Do Not Use Low Sulfur Diesel
Fuel (LSD)
Do not use fuel that is dispensed
from pumps bearing the LSD label.
Do Not Use Non-Highway Fuel
Fuel labeled as off road or
non-highway is typically very high in
sulfur content and will damage the
emission control system.
Non-highway fuel is not intended for
use in on-highway vehicles and
does not have the fuel properties
needed by the DPF-equipped
Duramax diesel.
In addition:
.Use the correct engine oil.
.Do not add gasoline to
diesel fuel.
.Do not modify the induction or
exhaust systems.
See Fuel for Diesel Engines on
page 9-21 and Engine Oil on
page 10-6.
Diesel Exhaust Fluid
Diesel Exhaust Fluid (DEF) is used
with diesel engines to reduce the
amount of regulated emissions
produced. The DEF system must be
maintained for the vehicle to run
properly.
Locating Diesel Exhaust Fluid
DEF can be purchased at a
Chevrolet or GMC dealer. It can
also be purchased at authorized
vehicle and truck dealerships.

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7132827) - 2015 - CRC - 10/21/14
1-4 In Brief
Additionally, some diesel truck
fueling stations or retailers may
have DEF for purchase. For
vehicles with an active OnStar
®
subscription, OnStar can help to
locate a DEF retailer. See
“Customer Assistance Offices”in
the owner manual for phone
numbers to assist you in contacting
a GM dealer. See Recommended
Fluids and Lubricants on page 11-8.
As the DEF tank becomes low on
fluid, warnings begin with
approximately 1 600 km (1,000 mi)
of remaining range. These warnings
will increase in intensity as the tank
becomes empty. Once the tank is
empty, the vehicle speed will be
limited. If there is an issue with the
quality of the fluid or the exhaust
fluid system, warnings will be
displayed in the Driver Information
Center (DIC). See Diesel Exhaust
Fluid on page 9-13.

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Instruments and Controls 5-1
Instruments and
Controls
Warning Lights, Gauges, and
Indicators
Instrument Cluster . . . . . . . . . . . . 5-2
Fuel Gauge . . . . . . . . . . . . . . . . . . . 5-6
Engine Oil Pressure Gauge . . . 5-7
Malfunction Indicator Lamp . . . 5-8
Wait-to-Start Light . . . . . . . . . . . 5-10
Diesel Exhaust Fluid (DEF)
Warning Light . . . . . . . . . . . . . . 5-11
Power Take-Off Light . . . . . . . . 5-11
Information Displays
Driver Information
Center (DIC) . . . . . . . . . . . . . . . . 5-11
Vehicle Messages
Vehicle Messages . . . . . . . . . . . 5-12
Engine Cooling System
Messages . . . . . . . . . . . . . . . . . . 5-13
Engine Oil Messages . . . . . . . . 5-13
Engine Power Messages . . . . 5-13
Fuel System Messages . . . . . . 5-13
Diesel Exhaust Fluid
Messages . . . . . . . . . . . . . . . . . . 5-13
Diesel Particulate Filter
Messages . . . . . . . . . . . . . . . . . . 5-14
Service Vehicle Messages . . . 5-14
Starting the Vehicle
Messages . . . . . . . . . . . . . . . . . . 5-15
Vehicle Speed Messages . . . . 5-15
Vehicle Personalization
Vehicle Personalization (Truck
Models) . . . . . . . . . . . . . . . . . . . . 5-16

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Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
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5-2 Instruments and Controls
Warning Lights, Gauges, and Indicators
Instrument Cluster
English Base Level Pickup Shown, Metric Similar

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Instruments and Controls 5-3
English Uplevel Pickup Shown, Metric Similar

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Chevrolet/GMC Duramax Diesel Supplement (GMNA Localizing-U.S./Canada-
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5-4 Instruments and Controls
English Denali Pickup Shown, Metric Similar

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Instruments and Controls 5-5
English Van Shown, Metric Similar

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5-6 Instruments and Controls
See the owner manual for warning
lights and gauges not listed in this
supplement.
Fuel Gauge
Metric Pickup Models
English Pickup Models
Metric Van Models
English Van Models
When the ignition is on, the fuel
gauge shows approximately how
much fuel the vehicle has left in the
tank. The gauge will first indicate
E (Empty) before the vehicle is out
of fuel, but the vehicle's fuel tank
should be filled soon.
An arrow on the fuel gauge
indicates the side of the vehicle the
fuel door is on.

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Instruments and Controls 5-7
Listed are four situations customers
may experience with the fuel gauge:
.At the gas station, the fuel pump
shuts off before the gauge reads
F (Full).
.It takes a little more or less fuel
to fill up than the fuel gauge
indicated. For example, the
gauge may have indicated the
tank was half full, but it actually
took a little more or less than
half the tank's capacity to fill
the tank.
.The gauge moves a little while
turning a corner or speeding up.
.The gauge does not go back to
E (Empty) when the ignition is
turned off.
None of these indicate a problem
with the fuel gauge.
For information on how to fill the fuel
tank, see Filling the Tank on
page 9-36.
Engine Oil Pressure
Gauge
Metric Pickup Models
English Pickup Models
Metric Van Models

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5-8 Instruments and Controls
English Van Models
{Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine
oil low can also damage the
engine. The repairs would not be
covered by the vehicle warranty.
Check the oil level as soon as
possible. Add oil if required, but if
the oil level is within the operating
range and the oil pressure is still
(Continued)
Caution (Continued)
low, have the vehicle serviced.
Always follow the maintenance
schedule for changing engine oil.
The engine oil pressure gauge
reads in kPa (kilopascals) or psi
(pounds per square inch) when the
engine is running. Oil pressure may
vary with engine speed, outside
temperature, and oil viscosity.
If readings are outside the normal
operating range, the low oil
pressure message may display on
the Driver Information Center (DIC),
or for vehicles without DIC the oil
pressure light will come on. If the oil
pressure message or light comes
on, check the oil level immediately.
Do not operate the engine with the
oil pressure warning light on or an
ENGINE OIL LOW ADD OIL
message displayed.
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors the operation
of the vehicle to ensure emissions
are at acceptable levels, helping to
maintain a clean environment. The
malfunction indicator lamp comes
on when the vehicle is placed in
ON/RUN as a check to show it is
working. If it does not, have the
vehicle serviced by your dealer. See
“Ignition Positions”in the owner
manual.
If the malfunction indicator lamp
comes on while the engine is
running, this indicates that there is
an OBD II problem and diagnosis
and service might be required.

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Instruments and Controls 5-9
This light may also come on when
the Diesel Exhaust Fluid (DEF)
management system is not working.
See Diesel Exhaust Fluid on
page 9-13.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system also
assists the service technician in
correctly diagnosing any
malfunction.
{Caution
If the vehicle is continually driven
with this light on, the emission
controls might not work as well,
the vehicle fuel economy might
not be as good, and the engine
might not run as smoothly. This
could lead to costly repairs that
might not be covered by the
vehicle warranty.
{Caution
Modifications made to the engine,
transmission, exhaust, intake,
or fuel system of the vehicle or
the replacement of the original
tires with other than those of the
same Tire Performance Criteria
(TPC) can affect the vehicle's
emission controls and can cause
this light to come on.
Modifications to these systems
could lead to costly repairs not
covered by the vehicle warranty.
This could also result in a failure
to pass a required Emission
Inspection/Maintenance test. See
Accessories and Modifications on
page 10-1.
When the light is on, an emission
control system malfunction has
been detected on the vehicle.
Diagnosis and service might be
required.
An emission system malfunction
might be corrected by using good
quality fuel. Poor fuel quality causes
the engine not to run as efficiently
as designed and may cause: stalling
after start-up, stalling when the
vehicle is changed into gear,
misfiring, hesitation on acceleration,
or stumbling on acceleration. These
conditions might go away once the
engine is warmed up. See Fuel for
Diesel Engines on page 9-21.
If this does not make the light turn
off, your dealer can check the
vehicle. The dealer has the proper
test equipment and diagnostic tools
to fix any mechanical or electrical
problems that might have
developed.
Emissions Inspection and
Maintenance Programs
Depending on where you live, your
vehicle may be required to
participate in an emission control
system inspection and maintenance
program. For the inspection, the

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5-10 Instruments and Controls
emission system test equipment will
likely connect to the vehicle's Data
Link Connector (DLC).
The DLC is under the instrument
panel to the left of the steering
wheel. See your dealer if assistance
is needed.
The vehicle may not pass
inspection if:
.The malfunction indicator lamp is
on with the engine running, or if
the light does not come on when
the ignition is turned to ON/RUN
while the engine is off. See your
dealer for assistance in verifying
proper operation of the
malfunction indicator lamp.
.The OBD II (On-Board
Diagnostics) system determines
that critical emission control
systems have not been
completely diagnosed. The
vehicle would be considered not
ready for inspection. This can
happen if the 12-volt battery has
recently been replaced or run
down. The diagnostic system is
designed to evaluate critical
emission control systems during
normal driving. This can take
several days of routine driving.
If this has been done and the
vehicle still does not pass the
inspection for lack of OBD II
system readiness, your dealer
can prepare the vehicle for
inspection.
Wait-to-Start Light
If the wait-to-start light comes on,
the glow plug system is required
and operating. Wait until the light
turns off before starting the engine.
This light may not come on in warm
temperatures.
The fast warm-up glow plug system
makes the wait-to-start light stay on
for a shorter amount of time than
most diesel engines.
See Starting the Diesel Engine on
page 9-1.

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Instruments and Controls 5-11
Diesel Exhaust Fluid
(DEF) Warning Light
This light, a Driver Information
Center (DIC) message, and a chime
come on when there is an issue with
the Diesel Exhaust Fluid.
See Diesel Exhaust Fluid Messages
on page 5-13 for information on the
specific message displaying with the
light.
If the DEF fluid level has not been
corrected, the light will continue to
flash when the vehicle is started.
The vehicle's speed may also be
limited.
Also see Diesel Exhaust Fluid on
page 9-13.
Power Take-Off Light
Non-Denali Pickups
The vehicle may have a Power
Take-Off (PTO) light. Under normal
operating conditions, the PTO light
will remain on throughout the PTO
operating cycle. If all conditions
required to engage PTO have not
been met when enabling PTO, the
PTO light will turn on, then turn off
after one second. See Power
Take-Off (PTO) on page 9-43.
Information Displays
Driver Information
Center (DIC)
The DIC is in the instrument cluster.
The DIC comes on when the ignition
is on.
A Duramax diesel vehicle may have
the following additional DIC menu
items.
EXHAUST FLUID LEVEL
The EXHAUST FLUID LEVEL will
be displayed as either OK, XX%,
or LOW.
When LOW appears on the display,
add diesel exhaust fluid as soon as
possible. See Diesel Exhaust Fluid
on page 9-13.