Fuel System Leak - GMC 2016 Silverado Manual

16 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.

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.
CNG is non-toxic but the
vapors are lighter than air
and can cause oxygen
depletion if they are
(Continued)
Warning (Continued)
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
natural gas leak. If the natural gas
is ignited, you or others could be
injured. 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 a
well-ventilated 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.