Page 15 of 29

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.
Page 17 of 29

Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
16 Vehicle Care
Vehicle Care
General Information
Accessories andModifications . . . . . . . . . . . . . . . . . 16
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . 16
Fuel System Components . . . . . 17
Wheels and Tires
Tire Changing . . . . . . . . . . . . . . . . . 19
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . 19
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . 20
General Information
Accessories and
Modifications
Adding accessories or making
modifications to the vehicle,
including to the CNG tank shields,
could cause damage and would not
be covered by the vehicle warranty.
If a CNG tank needs service or
repair, have only a qualified
technician perform the work. See
“Accessories and Modifications” in
the owner manual.
Vehicle Checks
Doing Your Own
Service Work
{Warning
Never try to do your own service
work on the Compressed Natural
Gas (CNG) fuel system. The CNG
fuel system operates under high
pressure. You can be injured and
the vehicle can be damaged if
you try to do your own service
work. Service and repair of this
system should only be performed
by a qualified dealer.
Page 19 of 29
Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
18 Vehicle Care
Manual Shutoff Valve
Locate the manual shutoff valve so
that it can be found quickly if it is
needed.
The manual shutoff valve is on the
driver side of the vehicle in front of
the rear tire.
A label is on the outside of the
vehicle near the manual shutoff
valve. Do not remove this label.To turn off the valve, turn the lever
one-quarter turn clockwise. Turn it
counterclockwise to turn the valve
back on.
Turn off the valve if a fuel leak is
suspected or the vehicle is involved
in an accident. This valve, when
turned, will stop CNG flow to the
engine.High Pressure CNG Fuel Filter
The high pressure CNG fuel filter is
under the rear of the vehicle. This
filter must have the water drained
and the filter element must also be
replaced at specific service
intervals. See
Maintenance
Schedule 021.
Page 20 of 29

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.