Chevrolet Low Cab Forward 2023 Manual page 157

156 Driving and Operating
DEF Disposal
Do not dispose of DEF and the empty
container into lakes, marine areas, rivers,
etc. DEF must be disposed of in a method
conforming to the regulatory requirements
in your state.
Selective Catalytic Reduction (SCR) System
The Selective Catalytic Reduction (SCR)
system reduces nitrogen oxide (NOx)
emissions emitted from a diesel engine. The
SCR system reduces NOx by adding
(injecting) Diesel Exhaust Fluid (DEF) into the
exhaust system and inducing a reaction
converting NOx into water vapor and
nitrogen. The SCR system consists of the
ECM, DEF tank, DEF Supply Pump and
Injector, and the SCR Catalyst. It is
important to keep a good supply of DEF in
the DEF tank at all times. Monitor the DEF
gauge to be sure the DEF tank level does
not become too low. If the DEF level
becomes too low or incorrect fluid is added
to the DEF tank, warning and indicator lights
will come on and engine power will be
reduced. If you see these warning and
indicator lights, add DEF as soon as possible
or have your vehicle serviced as soon as
possible. Continuing to drive for too long
after these lights come on will result in
additional warnings, more engine power
reduction and eventually in a severe vehicle
speed limitation.
Warning
Do not touch the water that comes out
from the muffler. The water is mildly
acidified due to the action of oxidation
catalyst inside the muffler. In the event
that the fluid does come into contact
with your skin, completely wash it off
with water. You and others could be
seriously injured.
Do not relocate or modify the exhaust pipe,
muffler, DPF, SCR, or DEF tank, which may
affect the exhaust gas cleaning performance.
If any relocation or modification is
necessary, consult your dealer.
The SCR system continues to operate for
approximately 3 minutes after the engine
control switch is turned to the "LOCK"
position. It is normal to hear a buzzing type
noise from the DEF supply pump (mounted
on the left side frame rail behind the cab)
during the shutdown process.
Diesel Exhaust Fluid (DEF) Low Level Warning
Diesel Exhaust Fluid (DEF) is a required fluid
for the operation of your diesel engine just
as diesel fuel is required. To avoid running
out of DEF your vehicle will turn on warning
and indicator lights and reduce engine
power in progressive stages to encourage
adding DEF.
The following is a summary of the diesel
exhaust fluid (DEF) low level warning lights,
indicator lights and engine power
reductions. Continuing to drive for too long
after these lights come on will eventually
result in a severe vehicle speed limitation.
These warning and indicator lights will go
out automatically and engine power will be
restored to normal after the SCR system
detects that the DEF tank is refilled
with DEF.