File in Section:

Service Bulletin

Bulletin No.:
Date:

PI1197
March, 2014

PRELIMINARY INFORMATION
Subject:

2015 Silverado HD and Sierra HD New Model Features and Service Guide

Models:

2015 Chevrolet Silverado 2500HD-3500HD
2015 GMC Sierra 2500HD-3500HD
Equipped with Gasoline, V8, 6.0L, SFI, E85 MAX, Iron — RPO L96 and Hydra-Matic™
6L90 6-Speed Automatic Transmission — RPO MYD
Equipped with Bi-Fuel Gasoline/CNG, V8, 6.0L, SFI, GEN 1 — RPO LC8 and
Hydra-Matic™ 6L90 6-Speed Automatic Transmission — RPO MYD
Equipped with Duramax® Diesel, V8, 6.6L, PTI, Turbo — RPO LML and Allison 1000
6-Speed Automatic Transmission — RPO MW7

Bulletin Purpose

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Chevrolet Silverado

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GMC Sierra
The purpose of this bulletin is to help the Service and Sales Department personnel become familiar with some of the
new features on the 2015 Silverado 2500HD-3500HD and Sierra 2500HD-3500HD trucks.

About the Vehicle
The new 2015 Silverado 2500HD-3500HD and Sierra 2500HD-3500HD pickup trucks feature many of the same
enhancements that made their debut on the 2014 Silverado 1500LD and Sierra 1500LD trucks, including the next
generation Chevrolet MyLink™ and GMC IntelliLink™ system, segment first safety technologies and cargo box
innovations.
The HD trucks are equipped with carryover chassis systems and powertrains from the previous generation HD
trucks that are proven, powerful and extremely reliable.
Some of the additional, new and/or enhanced features depending on the equipment package of the vehicle are as
follows:
– New 6.5-ft and 8-ft boxes with standard CornerStep rear bumpers combined with hand assists built into the box
rail protectors, EZ Lift and Lower tailgate, standard upper tie-downs and other features that make cargo handling
easier.
– New available box upper tie-down hooks, and under rail LED lighting.

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– An available spray-on bed liner, which bonds to the steel bed to create a permanent and water-tight protection for
the box. The spray-on bed liner covers the entire bed surface below the side rails, including the tailgate and front
box top rail.
– Standard StabiliTrak® with Trailer Sway Control on all models, including the 3500HD dually and cab chassis.
– Integrated Trailer Brake Control (ITBC) that is compatible with electric and now most electric over hydraulic brake
systems.
– Integrated cruise control, auto grade braking, Hill Descent Control (HDC) and Duramax ® diesel exhaust braking,
for greater driving control and reduced brake wear on grades (if equipped).
– The all new exterior of the vehicles enhances aerodynamics for improved efficiency and increased cooling airflow,
which enables the Duramax ® diesel and the 6.0L gas and/or 6.0L Bi-Fuel engine to better maintain full and
consistent power, even under heavy loads and high ambient temperatures.
– Available auxiliary bank switches on the base model Sierra and the Silverado WT.
– The latest generation Chevrolet MyLink™ infotainment system, which offers a variety of connectivity options for
devices of all types and available navigation.
– The latest generation GMC IntelliLink™ infotainment system, which offers a variety of connectivity options for
devices of all types and available navigation.

Pre-Delivery Inspection (PDI) and Preparation — Filling the DEF Tank Just Prior to
Delivery
Performing a quality pre-delivery inspection (PDI) is one of the most important functions the Service Agent (Dealer)
can do for the customer. Most customers consider the condition of their new vehicle during delivery as a direct
reflection of the Retailer and their Service Department.
A quality PDI is essential to improving a customer's perception of your facility and increasing his/her satisfaction with
their new vehicle.
• The 2015 Silverado HD form is available via Global Connect > Pre-Delivery Inspection Forms > 2015 Chevrolet
Pre-Delivery Inspection Forms > 2015 Silverado HD.
• The 2015 Sierra HD form is available via Global Connect > Pre-Delivery Inspection Forms > 2015 GMC
Pre-Delivery Inspection Forms > 2015 Sierra HD and Sierra Denali.
These forms contain the same generic PDI steps as before, but also include a section for Special Inspection Items.
This Special Inspection Items section is updated frequently and contains special items to look for during the PDI
process.
Report any product issues via Field Product Report. Refer to the latest version of Corporate Bulletin Number
02-00-89-002: Information for Dealers on How to Submit a Field Product Report (FPR). Canadian Dealers should
refer to the latest version of Corporate Bulletin Number 10-00-89-006: Information for Dealers on How to Submit a
Product Information Report (PIR) .
Filling the Diesel Exhaust Fluid (DEF) Tank Just Prior to Delivery
The DEF tank should be filled just prior to delivery to the customer. Use only exhaust fluid that is GM approved, or
fluid containing the API certified or ISO 22241 label.
The fluid claim should be submitted under the "0590052 PDI Related Fluid Adds" labor operation at the time of DEF
fill. Labor for filling the DEF is included in the base PDI time. The PDI add fluids are to be entered in the Net Miscellaneous field in GWM.

Customer Education
It is imperative that the customer be well informed about the unique features and operational characteristics of their
redesigned 2015 heavy duty trucks. For the sales team to be fully prepared, they should thoroughly review this New
Model Features and Service Guide and use the Getting to Know Your Vehicle (GTK) guide (available in the U.S.
only) as an outline when presenting the vehicle(s) to the customer. Additionally, Service and Parts leadership,
Service Writers and Service Technicians should familiarize themselves with these materials to avoid attempting
repair of normal operating characteristics.

Available Product Training
The majority of the systems found on the Silverado and Sierra are taught in GM’s core curriculum from a conceptual
theory and operation perspective.
New CNG Training Course: 16240.62W CNG Fuel Systems

To access all of the available training courses visit the following website:
• In the United States go to > www.centerlearning.com
and/or
Go to > Product Training > Launch Programs > Silverado or Sierra. Be sure to review the: GMC ProductSource
Website - B50PS.M10W for information regarding diesel exhaust fluid (DEF) , Diesel Exhaust Brake and other
important features.
• In Canada go to > www.gmprocanada.com

Available Engines — Recommended Fuel
Gasoline, V8, 6.0L, SFI, E85 MAX, Iron — RPO L96
Regular Unleaded Gasoline to Use: Use regular unleaded gasoline meeting ASTM specification D4814 with a
posted octane rating of 87 or higher. Do not use unleaded gasoline with an octane rating below 87, as it may cause
engine damage and will lower fuel economy.
Engine Performance Specifications:
– Silverado HD: 360 hp (268 kW) @ 5400 rpm and 380 lb-ft (515 Nm) @ 4200 rpm.
– Sierra HD: 360 hp (268 kW) @ 5400 rpm and 380 lb-ft (515 Nm) @ 4200 rpm
– Silverado HD > 10,000 lbs: (Cab Chassis Models Only) 322 hp (240 kW) @ 4400 rpm and 380 lb-ft (515 Nm) @
4200 rpm
In Canada, these engines are rated at 335 hp (250 kW)
– Sierra HD > 10,000 lbs: (Cab Chassis Models Only) 322 hp (240 kW) @ 4400 rpm and 380 lb-ft (515 Nm) @
4200 rpm
In Canada, these engines are rated at 335 hp (250 kW)
Bi-Fuel Gasoline/CNG, V8, 6.0L, SFI, GEN 1 — RPO LC8
Regular Unleaded Gasoline to Use: Use regular unleaded gasoline meeting ASTM specification D4814 with a
posted octane rating of 87 or higher. Do not use unleaded gasoline with an octane rating below 87, as it may cause
engine damage and will lower fuel economy.
CNG Fuel to Use: The general marketplace fuel quality of CNG for motor vehicles in the state of California should
be in compliance with Title 13 California Code of Regulations, Section 2292.5. The remaining regions of North
America do not employ regulated fuel quality standards for general marketplace vehicle usage, however, fuel is
available at both private and public filling stations. General Motors recommends the use of natural gas fuel from
fueling stations designed for providing fuel for motor vehicle use.
Engine Performance Specifications:
– Silverado HD: When using gasoline: 360 hp (268 kW) @ 5400 rpm and 380 lb-ft (515 Nm) @ 4200 rpm
– Silverado HD: When using CNG: 301 hp (225 kW) @ 5000 rpm and 333 lb-ft (452 Nm) @ 4200 rpm
– Sierra HD: When using gasoline: 360 hp (268 kW) @ 5400 rpm and 380 lb-ft (515 Nm) @ 4200 rpm
– Sierra HD: When using CNG: 301 hp (225 kW) @ 5000 rpm and 333 lb-ft (452 Nm) @ 4200 rpm
Duramax® Diesel, V8, 6.6L, PTI, Turbo — RPO LML

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Notice: Look for diesel fuel dispensers with this 15 ppm Sulfur Maximum Label. Permanent damage can
occur to the Diesel Particulate Filter (DPF) or related components if the required Ultra Low Sulfur Diesel Fuel
is not used. This damage would not be covered by the vehicle warranty.
Diesel Fuel to Use in The United States: Use only diesel fuel with an ultra low sulfur content of 15 ppm, maximum.
Use diesel fuel that meets ASTM specification D 975, Grades No. 2-D or No. 1-D S15, also known as Ultra Low
Sulfur Diesel. Contact a fuel suppler for any questions.
Biodiesel Blends to Use in The United States: Use biodiesel blends that meet the ASTM specification D6751.
Blends up to B5 must meet ASTM D975 Grades No. 2-D or No. 1-D S15 Ultra Low Sulfur Diesel. Blends containing
more than 5% and up to 20% biodiesel must meet ASTM specification D7467 Biodiesel blend, B6 - B20.
Diesel Fuel to Use in Canada: Use only diesel fuel with ultra low sulfur content, 15 ppm maximum. Use diesel fuel
that meets CAN/CGSB-3.517 specification in Canada. Biodiesel blends that meet the CAN/CGSB-3.522
specifications up to 20% (B20) can be used. Avoid the use of biodiesel blends above 20%, as they may damage the
engine and fuel system. Contact a fuel supplier for questions about fuel.
Biodiesel Blends to Use in Canada: Biodiesel blends that meet the CAN/CGSB-3.522 specifications up to 20%
(B20) can be used. Avoid the use of biodiesel blends above 20%, as they may damage the engine and fuel system.
Diesel Fuel to Use in Mexico: Use diesel fuel specification NOM-086 Pemex UBA, which meets the Ultra Low
Sulfur Diesel fuel requirement of 15 ppm sulfur maximum. This fuel is not available in all regions of Mexico.
Engine Performance Specifications:
– Silverado HD: 397 hp (296 kW) @ 3000 rpm and 765 lb-ft (1037 Nm) @ 1600 rpm
– Sierra HD: 397 hp (296 kW) @ 3000 rpm and 765 lb-ft (1037 Nm) @ 1600 rpm
Duramax® Elevated Cold Engine Idle Feature
The elevated cold engine idle feature for diesel can be toggled ON or OFF using the following procedure. The DIC
selection method is not available.
To turn this feature ON or OFF:
1. Turn the ignition to ON/RUN, with the vehicle OFF.
2. Press the accelerator pedal to the floor and hold while quickly pressing the brake pedal three times in less than
eight seconds.
3. Release the accelerator pedal and start the engine.

Transmissions — Transfer Cases
Hydra-Matic™ 6L90 6-Speed Automatic Transmission — RPO MYD
The Hydra-Matic™ 6L90 6-speed automatic has the following features:

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– Tow/Haul Mode adjusts the transmission shifts to reduce shift cycling, such as when towing or hauling heavy
loads or driving on steep grades. Press the Tow/Haul Mode button on the end of the shift lever to turn the system
ON or OFF.
– Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul Mode is selected and the vehicle is not in the
Range Selection Mode.
– Manual Mode — Range Selection Mode, if equipped helps control the vehicle's transmission and vehicle speed
while driving downhill or towing a trailer by letting you select a desired range of gears. To use this feature:
3.1. Move the shift lever to M (Manual Mode).

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3.2. Press the plus/minus buttons on the shift lever to select the desired range of gears for current driving
conditions.
The transmission will be limited to the gear selected and lower gears. If vehicle speed is too high or too low
for the requested gear, the shift will not occur.
Allison 1000 6-Speed Automatic Transmission — RPO MW7

The Allison 1000 6-speed automatic has the following features:
– Tow/Haul Mode that reduces shift cycling for better control and improved cooling when towing or hauling heavy
loads.
– Driver Shift Control (DSC) with tap-up/tap-down shifting.
– An available power take off (PTO) with a class leading 250 lb ft (339 Nm) of torque. The PTO is only available on
3500HD Cab Chassis vehicles.
Transfer Cases
The following transfer cases are available:
– Transfer Case – Manual Shift Control, Two Speed, Aluminum with floor mounted shifter — RPO NQG
– Transfer Case – Electric Shift Control, Two Speed, Aluminum with rotary dial controls — RPO NQF
Transfer Case Noise
Notice: Driving on clean, dry pavement in Four-Wheel Drive High or Four-Wheel Drive Low for an extended
period of time may cause premature wear on the vehicle's powertrain. The damage would not be covered by
the vehicle warranty.
The transfer cases for the HD trucks are carryover. Some customers may notice noise when operating in 4WD
especially on high traction surfaces such as dry pavement. While it is understood that operational noise is not
preferred, the transfer cases use heavy duty components in the interest of durability over quietness.
Power Take-Off (PTO) Operation and Instrument Cluster Light (3500HD Cab Chassis Vehicles Only)

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3500HD cab chassis vehicles 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.
Payload and Trailering Capabilities
–
–
–
–
–
–

Maximum Payload 2500HD: 4,306 lbs (1,953 kg)
Maximum Conventional Trailering 2500HD: 14,500 lbs (6,577 kg)
Maximum 5th Wheel Trailering 2500HD: 17,900 lbs (8,119 kg)
Maximum Payload 3500HD: 7,374 lbs (3,345 kg)
Maximum Conventional Trailering 3500HD: 19,600 lbs (8,890 kg)
Maximum 5th Wheel Trailering 3500HD: 23,200 lbs (10,523 kg)

Overview of Bi-Fuel Gasoline/CNG Operation

Overview
Notice: The Bi-Fuel Gasoline/CNG engine is currently only available in the 2500HD models.
The bi-fuel gasoline/CNG 6.0L V8 — RPO LC8 is very similar to past Model Years, with the exception of new
switchgear and messaging with the gauges and the DIC. The engine is equipped with special hardened valves and
valve seats to enable operation on gasoline or compressed natural gas (CNG), and will be available in all three
models of the new Silverado 2500HD and Sierra 2500HD: Regular Cab, Crew Cab and Double Cab (replaces the
Extended Cab). Chevrolet and GMC continue to work with a second-stage manufacturer to offer a single-source
option for its CNG vehicles. The bi-fuel trucks are built with the specially designed engine, the fuel system is installed
by GM’s Tier One supplier, and the completed vehicle is delivered directly to the customer. This process makes
ordering the bi-fuel option as seamless as ordering a truck powered by gas or diesel, and ensures the highest level
of durability, reliability and safety.
CNG Indicator Lamp
The CNG indicator lamp on the CNG fuel selector switch in the center stack shows the current fuel mode, indicates a
transition between fuels and if there is a system error.
– Off: Vehicle is currently operating on gasoline.
– On: Vehicle is currently operating on CNG.
– Flashing Slowly (Once per Second): Vehicle is awaiting changeover to selected fuel or has started the
changeover.
– Flashing Rapidly (10 Times per Second): CNG system error. The light will continue to flash rapidly until the
problem is corrected. See your Dealer.
CNG Fuel Selector Switch

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Whichever mode is selected, gasoline or CNG the vehicle always starts on gasoline. When the ignition is in ON/
RUN, press the CNG fuel selector switch to select between gasoline and CNG.
When CNG mode is selected, the vehicle will automatically transition from gasoline to CNG when conditions for
CNG operation have been met.
While waiting to transition, the fuel operation indicator lamp will be flashing at a rate of once per second. If the
vehicle is turned OFF in gasoline mode, when started it will remain in gasoline mode until the fuel selector switch is
pressed. At temperatures colder than 32°F (0°C), it may take 10 to 15 minutes for the vehicle to switch from gasoline
to CNG. If the fuel selector switch is pressed to switch to gasoline from CNG while driving, the engine will change to
gasoline operation. If operating in CNG mode and the CNG tank is emptied, the vehicle will automatically switch to
gasoline operation and the indicator light will flash continuously. Press the CNG fuel selector switch to stop the
indicator light flashing.
⇒ If the vehicle is heavily loaded, such as when towing a trailer up a grade, it may be prevented from switching to
CNG. Once the high loads are no longer present, the system will switch.
Always keep the gasoline tank at least one-quarter full. It is very important not to run the gasoline tank out of fuel.
The system will not switch over to CNG operation if the engine stalls while running on gasoline.

If the vehicle runs out of CNG fuel, it will automatically switch over to gasoline operation. For normal CNG operation,
fill the CNG fuel storage system until the fuel gauge or DIC fuel level indicator displays at least one-quarter full.
Fuel Gauge Operation

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The vehicle has a gasoline/CNG fuel gauge. When the ignition is ON, the gasoline/CNG fuel gauge indicates
approximately how much fuel is left in the tank. When the engine is running, the fuel gauge displays the level for the
type of fuel that is currently being used. The fuel level for the second fuel that is not being used (gasoline or CNG) is
displayed in the Driver Information Center (DIC). CNG quantity is affected by changes in fuel temperature and fuel
pressure.
– Gasoline Fuel Level: While operating on CNG, the gasoline fuel level can be viewed in the DIC.
– CNG Fuel Level: While operating on gasoline, the CNG fuel level can be viewed in the DIC.
Blue Diamond-Shaped CNG Label

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There is an identifying blue diamond-shaped CNG label on the rear of the vehicle. Do not remove this label. This
label is necessary for compliance with NFPA-52 regulations. Driving without this label may violate the laws or
regulations in some states. Replacement labels can be ordered from your Dealer.
CNG Fuel Tank Shield

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Warning: The CNG tank shield protects the fuel tank in a crash and from road hazards. Operation with the
shield removed may result in tank damage that could result in a rupture or possible explosion of the tank.
You or others could be injured or even killed. If you must remove a tank shield for any reason, e.g., tank
inspection or vehicle repair, always reinstall the shield before operating the vehicle.
Adding accessories or making modifications to the vehicle, including to the CNG tank shields, could cause a
malfunction or damage and would not be covered by the vehicle warranty.
To avoid damage to any fuel tanks and reduce the risk of explosion, all tank shields MUST be present. Do not drill,
modify, attach accessories, or use shields as a work surface. Do not use fire near shields or tanks.
CNG Fuel Tank Inspection
The CNG system requires the following inspection every 60 000 km (36,000 mi) or 36 months, whichever occurs
first: Visual inspection of the CNG fuel tank by a CSA International-certified inspector or authorized GM Dealer. For
more information, see your Dealer or visit: http://www.csa-international.org

CNG Fuel Tank Fuel Fill Valve/Receptacle — Manual Shut-Off
Notice: Do not add anything to the vehicle that will cover the CNG fuel storage system or restrict access to
the manual shutoff valve.

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Before filling either fuel tank, turn OFF the engine.
The CNG fuel tank fuel fill valve/receptacle (2) is behind the fuel door on the driver side of the CNG tank shield in the
pickup bed.
The manual shutoff (1) is near the CNG tank fuel fill valve/receptacle (2) on the driver side of the tank shield in the
pickup bed. A label is on the outside of the vehicle near the manual shutoff. Do not remove this label.
To turn OFF the CNG fuel, turn the manual shutoff lever (1) one-quarter turn clockwise.
CNG Fuel Tank Refueling Procedure
There are two methods of refueling: fast filling or slow filling. Fast filling is normally used in fuel stations for natural
gas vehicles. It takes about six to eight minutes to fill up the fuel tank. Slow filling is done with a vehicle refueling
appliance or a time-fill post provided by the fleet operator. Refueling time varies depending upon the refueling
system used.
Consult with the refueling station attendant or system provider. Always observe all safety recommendations and
operating instructions on the refueling equipment. When refueling, use a fuel fill nozzle that complies with ANSI/
CSA-NGV 1-2006 standards. Nozzles are designed according to their maximum fill pressure: P30 (blue handle) for
3,000 psi (20,684 kPa) and P36 (yellow handle) for 3,600 psi (24,800 kPa). The maximum fill pressure is 3,600 psi
(24,800 kPa). Refuel with a yellow P36 nozzle where available. Using a blue P30 nozzle will provide a partial fill only.
Depending on CNG fill station equipment/performance and environmental conditions, CNG fill volume will vary. This
will affect overall vehicle range.
Put the vehicle into P (Park) and turn OFF the engine prior to refueling. Remove the dust cap from the fuel fill valve/
receptacle (2), clean off any dirt or debris on the fuel fill valve/receptacle (2), and follow the refueling instructions on
the pump or provided by the station operator. Refueling will stop automatically when the tank is full. Wait for the high
pressure fuel to be purged from the hose before disconnecting. See the station operator for information on how the
line is purged. To disconnect the vehicle from the refueling station, remove the nozzle from the fuel fill valve/
receptacle (2). A hissing sound may be heard as a small amount of natural gas escapes. This is normal. Put the fill
valve dust cap on securely and close the fuel fill door.
CNG Specific Fuses — Fuse Location

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The bi-fuel system has two fuses that are part of the engine compartment wiring harness. Both fuses are in a plastic
holder that is mounted inside the engine compartment, near the accessory battery tray.

Brakes — New Brake Fluid for 2015
Notice: DO NOT use any brake fluid other than the part numbers identified in this section.
The new brake fluid has enhanced corrosion inhibitors and significant improvements in lubricity, engineered to
eliminate master cylinder squeak/noise.
• In the United States use GM P/N 19299818
• In Canada use GM P/N 19299819

Brakes — Performance Enhancement Systems and Descriptions
Brakes
The Silverado and Sierra and new to the Dual Rear Wheel trucks and the cab chassis also, are all equipped with a
TRW EBC460 4-wheel disc brake antilock brake system (ABS).
The electronic brake control module and the brake pressure modulator are serviced separately. The brake pressure
modulator uses a four circuit configuration to control hydraulic pressure to each wheel independently.
Performance Enhancement Systems
Depending on the vehicle equipment, the following additional vehicle performance enhancement systems may be
provided:
• Traction Control System (TCS) and StabiliTrak ®
• Dynamic Rear Proportioning
• Hill Start Assist (HSA)
• Hill Descent Control (HDC)
• Integrated Trailer Brake Control (ITBC)
• Trailer Sway Control (TSC)
Traction Control System (TCS) and StabiliTrak®

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®

The vehicles have a Traction Control System (TCS) and StabiliTrak , an electronic stability control system. These
systems help limit wheel spin and assist the driver in maintaining control, especially on slippery road conditions.