Bulletin No.: PI0834
Date: Oct-2012

Subject:

New Model Features and Information for Bi-Fuel Gasoline and Compressed Natural Gas (CNG) Pickup
Trucks (U.S. and Canada Only)

Models:

2013 Chevrolet Silverado 2500HD
2013 GMC Sierra 2500HD
Equipped with Vortec 6.0L V-8 RPO LC8 Engine
Equipped with Extended Cab Only
Equipped with Standard or Long Box
Equipped with Two-Wheel or Four-Wheel Drive

Attention:

This vehicle operates using gasoline or compressed natural gas (CNG). When servicing these vehicles,
please consult all applicable local, state/provincial and federal regulations relative to technician licensing,
tool and workplace requirements.

Introduction

The purpose of this bulletin is to introduce the new 2013 Chevrolet Silverado and GMC Sierra Bi-Fuel gasoline and compressed natural gas (CNG) pickup
trucks.
The following information will familiarize dealership service personnel with the vehicle’s engine, bi-fuel systems operation, identification of the CNG components,
their location and operation, in order to service these new vehicles.

•

A complete web training course on the Bi-Fuel System Operation, course #16240.70W.
The web course will provide the following:
–

How the bi-fuel system operates and performs in comparison to a traditional gasoline vehicle.

–

Identifies components involved in bi-fuel system operation and bi-fuel supply operations.

–

Bi-fuel diagnostic scenarios for a no start condition and improper CNG operation.

–

Bi-fuel inspection and maintenance process including leak checking and tank removal safety.

–

Vehicle storage.

1

•

The vehicle uses GM Service Part Numbers and all service parts including the gaseous fuel components are available through the GM Customer Care
and Aftersales (CCA) Parts Distribution System.

•

Technical assistance will be provided by TAC.

•

Vehicle diagnosis is accomplished using the Tech 2®/MDI.

•

Powertrain diagnostics and diagnostic trouble codes (DTCs) are the same as gasoline only engines.

•

The vehicle comes with a Silverado/Sierra Bi-Fuel (Gasoline/CNG) Supplement to the Owner Manual.

About the Vehicle
The 2013 Chevrolet Silverado 2500HD and GMC Sierra 2500HD will be available with extended cab only, standard or long bed and either 2-wheel drive or 4wheel drive. The vehicle is available in all trim levels.
The Vortec 6.0L V-8 engine seamlessly transitions between gasoline and CNG.
The system design provides for primary operation on CNG as long as there is sufficient fuel in the CNG fuel tank and there are no mechanical or electrical
problems detected within the system.
With the 36 gallon (136.2 L) gasoline tank and the 17.5 GGE (66.2 L) CNG tank the combined range of the vehicle is more than 650 miles (1046 km).
Notice: It is very important to know how much weight the vehicle can carry. This weight is called the vehicle capacity weight and includes the
weight of all occupants, cargo, and all non-factory installed options. Two labels on the vehicle show how much weight it was designed to carry,
they are the Tire and Loading Information label and the Certification/Tire label. Refer to Vehicle Load Limits in SI.
The payload of the vehicle is reduced only by the weight of the CNG system and full fuel load which is 620 lbs.

Applicable Warranty Coverage

•

All components 100 % GM warranty.

•

3 Year/36,000 Miles (60,000 km) New Vehicle Limited Warranty.

•

5 Year/100,000 Miles (160,000 km) Powertrain Warranty.

•

Emissions Warranty (Varies by State).

•

All Warranties Fully Transferable — No Transfer Fee.

Bi-Fuel Gasoline and Compressed Natural Gas (CNG) Engine Technology

The Vortec 6.0L V-8 engine utilizes an engine control module (ECM) with both gasoline and CNG calibrations, designed to ensure all engine operating
parameters are within acceptable performance operating limits. The engine has the following features:

•

The engine is designed to meet strict Environmental Protection Agency (EPA) and California Air Resources Board (CARB) certification.

•

A gasoline fuel injection system.

•

A CNG fuel injection system.

•

The hardened bi-fuel engine provides the same durability as a gasoline only engine.

•

Fuel system corrosion resistance.
2

•

Fuel system integrity and crash worthiness.

•

Hardened engine components for CNG fuel usage as follows:

–

Hardened intake and exhaust valve seats (1).

–

Hardened exhaust valves (2).

Starting the Engine
Starting the engine in the bi-fuel vehicle is the same as starting a gasoline engine. The engine always starts on gasoline. Then, when the engine reaches a
pre-determined operating temperature it seamlessly switches over to the CNG fuel system. If the CNG fuel is depleted, the system will automatically switch over
to the gasoline system.
Always maintain a minimum gasoline level of at least one-quarter tank. To protect engine components, a switch to gasoline may occur at any time. The vehicle
will not start if the engine stalls due to a lack of gasoline.

Fuel Mode Switch and Indicator / LED Fuel Gauge / Switching Between Fuels
The CNG fuel mode switch and LED fuel gauge is integrated into the dash.
When the ignition is ON, or the engine is running the CNG fuel gauge indicates how much CNG is left in the tank.
The CNG fuel gauge will display full at approximately 3,600 psi (24,800 kPa) at 70°F (21°C) and empty at approximately 500 psi (3,447 kPa) at 70°F (21°C).
CNG quantity is affected by changes in fuel temperature and fuel pressure.

The single light at the top of the button at the 12 o’clock position, indicates which fuel system (mode) is currently in operation. The mode light will display one of
three colors to indicate the current operating mode as follows:
–

Red: Indicates the system is operating in gasoline mode.

–

Orange: Indicates the system is changing over from gasoline to CNG. Typically this is only ON for 1–2 seconds.

–

Green: Indicates the system is operating in CNG mode.

The four lights at the bottom of the button are the CNG fuel gauge and indicate the CNG fuel level as follows:
–

4 LEDs illuminated: Full Tank to 85 % (approximately 3,600–3,100 psi (24,800–21,400 kPa)

–

3 LEDs illuminated: 85 % to 50 % (approximately 3,100–1,875 psi (21,400–13,000 kPa)
3

–

2 LEDs illuminated: 50 % to 25 % (approximately 1,875–1,000 psi (13,000–6,900 kPa)

–

1 LED illuminated: 25 % to 15 % (approximately 1,000–500 psi (6,900–3,450 kPa)

–

1 LED Flashing: “Low Fuel Level” from 15 % to 0 % Usable (approximately 500–0 psi (3,450–0 kPa)

The driver can press the center of the button to switch between fuels at almost any time. The fuel mode can be changed almost any time the ignition is ON, or
the engine is running.

Malfunction Indicator Lamp (MIL)
This vehicle has been specifically designed to illuminate the malfunction indicator lamp (MIL) when emissions exceed acceptable levels while operating on
gasoline or CNG fuel.
The MIL will illuminate to indicate that there is a problem and service is required. Malfunctions often will be indicated by the system before any problem is
apparent.
This system is designed to assist the service technician in correctly diagnosing any malfunction.

CNG Blue Diamond Identification Label

Notice: There is an identifying blue diamond-shaped CNG label on the lower right rear of the tailgate. DO NOT remove this label. This label is
necessary for compliance with NFPA-52 regulations and insuring the vehicle. Driving without this label may violate the laws or regulations in
some States or Provinces. Replacement labels can be ordered from your dealer.

CNG Fuel and Standards
In the United States, the compressed natural gas used to refuel the vehicle must meet SAE J1616, or in the state of California, Title 13 California Code of
Regulations, Section 2292.5, standards for fuel composition and quality. If a fuel is used that does not meet these standards, there may be a decrease in engine
power and the emission controls can be damaged.
The main component of CNG is methane, a highly flammable, colorless gas. An odorant has been added for detection through smell. While it is the same natural
gas that is delivered to homes for domestic use, the CNG in the vehicle is stored under high pressure at a maximum of 3,600 psi (24,800 kPa).
The CNG system in the vehicle, including the tank, tubing and all other components on the high pressure side of the system, have been designed to hold gas at
this pressure. It has also been tested for safety.
4

Gas should never be smelled or a hissing sound should not be heard, unless refueling is being done. If gas is smelled or a hissing sound is heard, at ANY other
time, shut down the CNG system. It may be possible to hear the fuel flowing while the engine is running if standing close to the pipework or various fuel system
components such as the regulator or filter. This is normal and should not be confused with a hissing sound at fittings that may indicate a fuel leak.

Refueling Station Information
The system is designed to be filled at a 3,600 psi (24,800 kPa) refueling station.
The system can be filled at a 3,000 psi (20,700 kPa) refueling station, however this will result in a reduced range of operation.
In the United States, for up-to-date information on public-access CNG station locations and prices, and to view or add user comments, see:
www.cngnow.com, www.cngprices.com and www.cngchat.com
In the United States, public and private CNG stations may also be found at the following federal government website:
http://www.afdc.energy.gov/afdc/locator/stations/

CNG Fuel Supply and Metering Components
The CNG fuel supply and metering system consists of the following components:

•

CNG 1/4 Turn Isolation Valve (Manual Shut-Off Valve)

•

Alternative Fuel Rail Pressure/Temperature Sensor

•

CNG Coalescing Fuel Filter

•

CNG Cut-Off Solenoid Valves (2 Solenoid Valves)

•

Engine Control Module (ECM)

•

Excess Flow Valve

•

Fill Line Check Valve

•

Fill Filter

•

Fill Valve (NGV1 Fill Receptacle)

•

Fuel Injectors / Injector Hoses

•

Fuel Injector Control Module (FICM)

•

Fuel Injector Rails

•

Fuel Mode Switch

•

CNG Fuel Pressure Regulator

•

Fuel Pump Disable Module

•

CNG Fuel Tank

•

CNG Fuel Tank Pressure (FTP) Sensor

•

CNG Fuel Tank Temperature Sensor

•

CNG Tank Pressure Relief Device (PRD) (2 Devices)

•

High Pressure Line and Hose (Stainless Steel Tubing and Stainless Steel Jacketed PTFE Hose)

•

LED Fuel Gauge

•

Low Pressure Fuel Line and Hose (Stainless Steel Tubing and Stainless Steel Jacketed PTFE Hose)

CNG Components / Description and Operation / Component Location
CNG 1/4 Turn Isolation Valve (Manual Shut-Off Valve)

5

Notice: The handle on this 1/4 turn isolation valve (1) (manual shut-off valve) is RED and is located under the CNG fuel tank door as shown. This
valve is shown in the ON position.
The high pressure fuel system is equipped with a manually operated 1/4 turn isolation valve (1) (manual shut-off valve), located in the high pressure supply line
near the CNG fuel tank outlet (driver side). A label applied to the inside of the CNG fuel tank door, indicates the approximate location of this valve.
The purpose of the valve is to isolate the high pressure side of the fuel system for some service procedures. If this valve is inadvertently left in the OFF
position, the vehicle will not operate in CNG mode.
Turn the manual shut-off valve (1) 90 degrees to turn OFF the CNG.

Alternative Fuel Rail Pressure/Temperature Sensor

The alternative fuel rail pressure temperature sensor (1) is mounted to the right side fuel rail. It is a 4 wire sensor that provides the ECM with pressure and
temperature data through the FICM serial data.

CNG Coalescing Fuel Filter

6

The coalescing fuel filter is located between the front CNG cut-off solenoid valve 1 and the 1/4 turn isolation valve (manual shut-off valve). The coalescing filter
housing contains a 6 micron filter element and a drain fitting. The coalescing filter is designed to trap contaminates and liquids that may damage the fuel