
Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
6 Instruments and Controls
Vehicle Messages
Fuel System Messages
FUEL MODE UNAVAILABLE
This message displays when the
current fuel mode selected is empty
or unavailable. See“Fuel Selector
Switch” underFuel08. The vehicle
will switch fuel modes automatically.
This is usually due to a low fuel
condition of the fuel type selected or
the engine is not warm enough after
an initial engine start up.
This message will also appear if the
vehicle has initiated a gasoline
system maintenance routine.
A switch to CNG will not be
available until this routine is
complete.
This message can also appear if a
transition to CNG is attempted in
cold start conditions. See “Cold
Weather Starting” underStarting the
Engine 07. This message may also appear if
the CNG tank valve is unable to
open fully during some vehicle
operating conditions.
SERVICE FUEL SYSTEM PARK
IN OPEN AREA
This vehicle is equipped with a CNG
fuel system diagnostic to ensure
proper function. This message
displays when the CNG fuel system
requires service.
Park the vehicle in an outdoor open
area, do not start the engine, refuel,
or drive the vehicle. Have the
vehicle towed to an authorized GM
dealer for service.
See
Fuel System Leak 014.

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
Driving and Operating 7
Driving and
Operating
Driving Information
Vehicle Load Limits . . . . . . . . . . . . . 7
Starting and Operating
Starting the Engine . . . . . . . . . . . . . . 7
Ride Control Systems
Traction Control/ElectronicStability Control . . . . . . . . . . . . . . . . 8
Fuel
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Filling the Tank (CNG) . . . . . . . . . . 9
Fuel System Leak . . . . . . . . . . . . . 14
Trailer Towing
Trailer Towing . . . . . . . . . . . . . . . . . . 15
Driving Information
Vehicle Load Limits
Caution
Loose items stored in the cargo
area may damage the CNG fuel
tank and fuel system
components. Secure all items in
the cargo area to avoid shifting
and any damage to the CNG fuel
tank and CNG fuel tank
components.
Starting and
Operating
Starting the Engine
Starting the engine in a CNG
vehicle is similar to starting a
gasoline engine. See “Starting the
Engine” in the owner manual.
Fuel Selection
A switch allows the selection of fuel.
See Fuel 08. The vehicle typically
defaults to the fuel used on the last
key cycle.
If a tank refill has occurred after an
automatic low fuel level transition
from one fuel to another, CNG to
gasoline for example, the vehicle
recognizes the refill and if conditions
are met, will start on the fuel last
selected on the switch.
To protect engine and gasoline fuel
system components, an automatic
switch to gasoline may occur at any
time. The vehicle will transition back
to CNG automatically once the
gasoline system has run for a pre–
set time.

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
10 Driving and Operating
Warning (Continued)
gas is ignited. If you suspect a
leak, do not start the engine or
drive the vehicle. Have the
vehicle immediately towed,
inspected, and repaired by an
authorized GM dealer.
Before filling either fuel tank, turn off
the engine.
The gasoline tank is filled through
the standard fill pipe. See “Filling
the Tank” under“Fuel” in the owner
manual.
The CNG fill receptacle is behind
the fuel door on the passenger side
above the gasoline cap.
Refueling Procedure
There are two methods of refueling:
fast fill or time fill. Fast fill is
normally used in fuel stations for
natural gas vehicles. It takes about
two to five minutes to fill up the fuel
tank. Time fill is done with a
refueling appliance, including
residential appliances, 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. If a 24 800 kPa
(3,600 psig) nozzle is not available,
a 20 684 kPa (3,000 psig) nozzle
may be connected to the vehicle.
A fuel nozzle less than 7.6 cm (3 in)
long may be difficult to disengage
after dispensing CNG. During fueling, CNG needs to be
delivered to the vehicle at the
appropriate pressure in relationship
to the ambient temperature. This
can be done automatically by a
temperature compensation system
on the CNG fuel dispenser or
manually by stopping the CNG fill at
a recommended pressure related to
the ambient temperature
compensation chart. GM
recommends that customers use
CNG fueling stations that have a
temperature compensation system
whenever possible. Check with the
fuel station. If one is not available,
see the temperature compensation
chart that follows in this section to
choose the appropriate fill pressure
for the ambient temperature. In
addition, fill only to the pressure
level for the lowest ambient
temperature anticipated during
fueling.
Leaving a vehicle connected to a
time fill station can cause the tank
to be filled to a higher pressure than
recommended, especially when
outside temperatures fluctuate.
Disconnect the vehicle from the time

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
14 Driving and Operating
Pressure Relief Devices
The CNG tank has pressure relief
devices that are designed to release
pressure if the CNG tank is
overheated or over pressurized.
If a pressure relief device releases
CNG, the CNG tank will be emptied
and will switch to gasoline,
if gasoline is available. A loud
rushing noise may be heard when
CNG is released.
In Case of a CNG Leak
If a CNG fuel leak is suspected, see
Fuel System Leak014.
Fuel System Leak
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
. Keep all smoking materials
and sources of ignition away
from the fuel system
components.
(Continued)
Warning (Continued)
.CNG is non-toxic but the
vapors are lighter than air
and can cause oxygen
depletion if they are
enclosed in a confined
space. Make sure there is
adequate ventilation and
use extreme caution if a
leak is suspected.
{Warning
If you smell a persistent natural
gas odor or hear a continual
hissing sound, there could be a
CNG leak. If the gas is
accidentally ignited, you or others
could be seriously injured or
killed. Do not start the engine or
drive the vehicle. Have the
vehicle towed to an authorized
GM dealer for service. A slight natural gas odor may be
detected for a few moments after
refueling. This is normal. You should
not be able to smell natural gas at
any other time. If you do, or if you
hear a hissing sound, the fuel
system may have a leak.
If natural gas is smelled or a hissing
sound is heard:
1. Park the vehicle in an outdoor open area and apply the
parking brake. Keep heat,
sparks, and flame away. Open
all the vehicle doors for
ventilation.
2. Turn the ignition to LOCK/OFF. Do not start the engine, refuel,
or drive the vehicle.
3. The manual shutoff is on the driver side of the vehicle in
front of the rear tire. See Fuel
System Components 017.

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
Driving and Operating 15
A label is on the outside of the
vehicle near the manual shutoff
valve. Do not remove this label.
Turn the lever one-quarter turn
clockwise to turn off.
Do not drive the vehicle. Have the
vehicle towed to an authorized GM
dealer for service.Trailer Towing
The vehicle is neither designed nor
intended to tow a trailer.

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
Vehicle Care 19
Low Pressure CNG Oil Separator
The low pressure CNG oil separator
is under the hood on the driver side
of the vehicle. This filter must have
the oil drained periodically. See
Maintenance Schedule021.
Wheels and Tires
Tire Changing
Storing a Flat Tire
{Warning
Storing a jack, a tire, or other
equipment in the passenger
compartment of the vehicle could
cause injury. In a sudden stop or
collision, loose equipment could
strike someone. Store all these in
the proper place.
1. Replace the foam, jack, and tools as instructed in the owner
manual.
2. Replace the floor cover.
3. Place the tire, lying flat, in the trunk.
Jump Starting
Jump Starting - North
America
{Warning
If the CNG fuel system has a
leak, a spark from the jumper
cables could ignite the natural
gas, causing injury or death. Do
not jump start the vehicle if you
smell a persistent natural gas
odor or hear a continual hissing
sound. Close the manual shutoff
valve, and have the vehicle towed
to an authorized GM dealer for
service. See Fuel System
Components 017.
See “Jump Starting - North America”
in the owner manual.

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
28 Index
L
LampsMalfunction Indicator . . . . . . . . . . . . 4
Leak Fuel System . . . . . . . . . . . . . . . . . . . . 14
Lights Low Fuel Warning . . . . . . . . . . . . . . . 5
Low Fuel Warning Light . . . . . . . . . . . 5
M
Maintenance Schedule . . . . . . . . . . 21
Malfunction Indicator Lamp . . . . . . . 4
Messages Fuel System . . . . . . . . . . . . . . . . . . . . . 6
N
Natural GasVehicle Service Records . . . . . . . . 23
Natural Gas Vehicle (CNG) Service Records . . . . . . . . . . . . . . . 23
P
Proposition 65 Warning,California . . . . . . . . . . . . . . . . . . . . . . . 19
S
ServiceAccessories andModifications . . . . . . . . . . . . . . . . . . 16
Doing Your Own Work . . . . . . . . . . 16 Service (cont'd)
Engine Soon Light . . . . . . . . . . . . . . . 4
Service and Maintenance Natural Gas Vehicle (CNG)
Service Records . . . . . . . . . . . . . . 23
Specifications and Capacities . . . . 26
Starting the Engine . . . . . . . . . . . . . . . 7
Supplement Using . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
T
Tires
Changing . . . . . . . . . . . . . . . . . . . . . . . 19
Towing
Trailer . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Traction Control/Electronic Stability Control . . . . . . . . . . . . . . . . . 8
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . . 15
U
Using This Supplement . . . . . . . . . . . 2
V
Vehicle
Canadian Owners . . . . . . . . . . . . . . . 2
Load Limits . . . . . . . . . . . . . . . . . . . . . . 7