2018 CHEVROLET LOW CAB FORWARD warning light

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
164 Driving and Operating
The DPF performs regeneration
automatically when a certain
quantity of PM accumulates in the
filter.
Depending upon running conditions,
however, the regeneration may
sometimes not be completed. In this
case, the regeneration required
warning light (amber) will come on,
so promptly operate the emergency
regeneration according to the
Emergency Regeneration
Procedure. This operation recovers
the function of the DPF. It does not
mean that a breakdown has
occurred.
The engine speed may increase
and the exhaust brake may activate
while the vehicle is stopped with the
engine idling. When this occurs, the
DPF is automatically regenerated.
This does not indicate a failure.
The system generates a sound
during the automatic regeneration
and its cancellation. This does not
indicate a failure.DPF SwitchThe DPF switch is used to burn PM
(regenerate the filter). You can
initiate regeneration when the
regeneration required warning light
or selectable (switch) regeneration
required warning light turns on with
short repeated beeps.
Continuing driving without
performing the regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on.
The DPF then must be repaired at
the nearest dealer.
Emergency Regeneration
Procedure
If the regeneration required warning
light (amber) or selectable (switch)
regeneration required warning light
(amber) turns on the DIC, the DPF
could not satisfactorily complete
automatic regeneration and driver
action is required. If the
regeneration required warning light
(Not selectable (switch)
regeneration warning light) is turned
on, you can choose from Running

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 165
regeneration or Switch regeneration
in order to complete the DPF
regeneration.
If the selectable (switch)
regeneration required warning light
turns on, you have to perform
Switch regeneration in order to
complete the DPF regeneration.
If you continue driving too long with
the regeneration required warning
light (amber) or selectable (switch)
regeneration required warning light
(amber) displayed on the DIC
without performing one of the
possible regenerations, the
message will change to red
Regeneration Required warning
light or selectable (switch)
regeneration required warning light.
The red regeneration required
warning light or selectable (switch)
regeneration required warning light
indicates the DPF filter is nearly full
of PM, a condition which may be
damaging to the filter.
DPF regeneration should be
completed immediately if the red
regeneration required warning lightor selectable (switch) regeneration
required warning light is displayed
on the DIC.
Continuing to drive without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Driver Information Center (DIC)
0
82.
Running Regeneration Procedure
Use this option for completing DPF
regeneration, if driving conditions
and traffic allow you to maintain a
relatively constant speed above
48 km/h (30 MPH) for about
20 minutes.
Follow the steps below to use
Running regeneration: 1. Determine if road and traffic conditions allow for relatively
constant speeds above
48 km/h (30 MPH).
2. Increase the vehicle speed above 48 km/h (30 MPH) and
keep a constant speed. 3. When vehicle speed, engine
coolant temperature and other
factors are met the engine
control module (ECM) will
begin DPF regeneration and
the regeneration in progress
indicator light (amber) will
appear on the DIC.
4. Continue driving until the regeneration in progress
indicator light (amber) goes off.
When this indicator light goes
off the DPF regeneration is
complete.
See Driver Information Center (DIC)
0 82.
While the vehicle is at a stop with
engine idling, the engine speed
increases.
Switch Regeneration Procedure

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
166 Driving and Operating
{Warning
To prevent a fire, make sure that
there is no flammable material
near the muffler, DPF and
exhaust pipe. Remember that the
temperature of exhaust gases is
high enough to burn you. You and
others could be seriously injured.
Select Switch regeneration
procedure if the Running
regeneration procedure is not
possible, or if the selectable (switch) regeneration required warning light
(amber or red) is displayed on
the DIC.
1. Stop the vehicle at a safe place free of flammable material such
as dead grass, leaves or waste
paper.
2. Move the selector lever into the P position and firmly engage
the parking brake.
3. Let the engine idle. Be sure the accelerator pedal is not
pressed and the PTO switch (if
equipped) is OFF.
4. Press and release the DPF switch.
5. The regeneration required warning light (amber or red) or
selectable (switch)
regeneration required warning
light (amber or red) on the DIC
will turn off and the
regeneration in progress
indicator light will appear.
6. Do not leave the vehicle during the regeneration. Regeneration
normally completes in about
20 minutes. 7. When the regeneration in
progress indicator light (amber)
goes out, regeneration is
completed. Normal driving is
then possible.
If the Switch regeneration is
interrupted, a selectable (switch)
regeneration required warning light
(amber) will appear on the DIC. You
must complete the DPF
regeneration by performing the
Switch regeneration once again as
soon as possible.
If you continue driving too long with
the selectable (switch) regeneration
required warning light (amber)
displayed on the DIC, the message
will change to red. The selectable
(switch) regeneration required
warning light (red) indicates the
DPF filter is nearly full of PM, a
condition which may be damaging
to the filter.
DPF regeneration should be
completed immediately if the
selectable (switch) regeneration
required warning light (red) is
displayed on the DIC.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 167
Continued driving without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Driver Information Center (DIC)
082.
When operating the PTO for a long
time if your vehicle is so equipped,
make sure that the regeneration
required warning light or selectable
(switch) regeneration required
warning light (amber) is not
turning on.
Once the Switch regeneration is
started, it cannot be switched to the
Running regeneration if interrupted.
When the Switch regeneration is
selected, end regeneration in a
single operation if possible.
During the regeneration, the engine
speed may vary, causing the
exhaust brake valve to be
deactivated. However, while the
regeneration in progress indicator
light (amber) appears, regeneration is still taking place, so continue to
perform regeneration until the
message goes off.
The time needed to complete
regeneration differs depending on
the outside temperature.
The exhaust brake or exhaust
throttle is activated during DPF
regeneration. The exhaust brake or
exhaust throttle starting to operate
or being disengaged will produce a
sound, but this does not indicate a
failure.
During regeneration, white smoke
may be temporarily produced from
the exhaust pipe. This results from
combustion of PM, it does not
indicate a failure.
Switch regeneration will complete
earlier immediately after driving than
when the engine is cold.
The engine coolant temperature
may rise during switch regeneration.
Interruption of Switch
Regeneration
If you must interrupt regeneration for
an unavoidable reason, press the
DPF switch again.
The regeneration in progress
indicator light (amber) changes to
the selectable (switch) regeneration
required warning light (amber).
Then, you can drive the vehicle.
If you interrupt regeneration, you
need to perform regeneration again.
Perform switch regeneration
beginning with Step 1 as soon as
possible.
Switch regeneration will be
interrupted in the following
circumstances:
.
Accelerator pedal is pressed.
. Gear-in.
. Vehicle speed is above
0 km/h (0 MPH).
. Engine speed increases.
Operation noise caused by
interruption is louder when pressing
the accelerator pedal than other
operations. This is not a failure.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 169
3. Run the engine at idle. Be surethe accelerator pedal is not
pressed and the PTO switch (if
equipped) is OFF.
4. Press and hold the DPF switch until the amber checking PM
Level indicator light appears on
the DIC.
5. If Selectable regeneration is available, the selectable
(switch) regeneration required
warning light (amber) will
appear on the DIC. If this
indicator light does not appear
on the DIC, the PM level in the DPF filter is OK and DPF
regeneration is not needed at
this time.
6. Press and release the DPF switch to begin regeneration.
7. The selectable (switch) regeneration required warning
light (amber) will change to
regeneration in progress
indicator light.
8. Do not leave the vehicle during the regeneration. Regeneration
normally completes in about
20 minutes, if the engine is at operating temperature.
Regeneration may take longer
if the engine is cold.
9. When the regeneration in progress indicator light goes
out, the Selectable
regeneration is complete.
If the Selectable regeneration is
interrupted, a selectable (switch)
regeneration required warning light
(amber) will appear on the DIC. You
must complete the DPF
regeneration by performing the
Switch regeneration as soon as
possible when Selectable
regeneration is interrupted.
If you continue driving too long with
the selectable (switch) regeneration
required warning light (amber)
displayed on the DIC, the warning
light will change to red. The
selectable (switch) regeneration
required warning light (red) indicates
the DPF filter is nearly full of PM, a
condition which may be damaging
to the filter. DPF regeneration
should be completed immediately if

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
170 Driving and Operating
the selectable (switch) regeneration
required warning light (red) is
displayed on the DIC.
Continued driving without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Vehicle Messages086.
The time needed to complete
regeneration differs depending on
the outside temperature.
The exhaust brake is activated
during DPF regeneration. The
exhaust brake starting to operate or
being disengaged will produce a
sound, but this does not indicate a
failure.
During regeneration, white smoke
may be temporarily produced from
the exhaust pipe. This results from
combustion of PM, it does not
indicate a failure.
Regeneration is finished earlier
immediately after driving than when
the engine is cold. The engine coolant temperature
may rise during regeneration.
DPF Regeneration during
Prolonged Idling
DPF regeneration may be initiated
automatically during prolonged
idling. If regeneration is initiated, the
regeneration in progress indicator
light (amber) comes on but this is
normal and does not indicate a
failure.
If driving is started or the PTO is
connected during DPF regeneration
by prolonged idling, the selectable
(switch) regeneration required
warning light (amber) comes on and
regeneration is suspended. Perform
Switch regeneration procedure in
order to complete the DPF
regeneration.
Prolonged idling may require more
frequent DPF regeneration.
See
Driver Information Center (DIC)
0 82.Diesel Exhaust Fluid
Diesel exhaust fluid (DEF) is used
exclusively for the selective catalytic
reduction (SCR) system. Be sure to
use only API certified DEF. When
the SCR system detects DEF level
is nearly empty or incorrect fluids
(such as water or low concentrated
DEF.) are added, the SCR system
will turn on warning and indicator
lights and reduce engine power in
progressive stages to encourage
you to have the condition corrected.
Continuing to drive for too long after
these lights come on will eventually
result in a severe vehicle speed
limitation. See Vehicle Messages
0 86
The DEF freezes below −11 °C
(12 °F). The SCR system is
equipped with a heating function
which utilizes the engine coolant, so
the engine can be started even
when DEF is frozen.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 173
Warning (Continued)
Do not add substances such as
gasoline or diesel fuel to the DEF
tank. You and others could be
seriously injured.
Caution
When opening the DEF tank cap,
be careful not to let dirt or other
foreign matter enter inside the
DEF tank. Intrusion of foreign
matter can cause a clogging of
the filter or affect the quality of
DEF, which may result in a SCR
system failure.
If DEF is spilled on the body or
frame, it may cause generation of
rust, so wipe it off and then rinse
it away with water.
When DEF dries it will leave a
crystalline residue, this condition is
normal. Wash with water or wipe
away the residue to prevent it from
entering the DEF tank. Adding DEF in Cold Weather
DEF freezes at low temperature but
the engine coolant circulates to
thaw the DEF tank and to prevent
DEF from freezing. Vehicle can be
driven normally when DEF is frozen.
If the refill diesel exhaust fluid (DEF)
warning light is on and the
remaining DEF in the DEF tank is
frozen, the warning lights, indicator
lights and restriction will not be
canceled until the DEF thaws even
if the DEF tank is refilled.
It is not recommended parking the
vehicle for long periods with the refill
diesel exhaust fluid (DEF) warning
light on in cold weather. The DEF
gauge will not register correctly
should the DEF freeze in this
condition causing the DEF low level
warning system not to reset when
DEF is added. Take the following
actions to avoid this condition in
cold weather:
1. Refill the DEF as soon as possible after parking the
vehicle. 2. Turn the engine control switch
to the ON position from the
LOCK position.
3. Wait for the warning buzzers and warning lights to turn off.
4. If the buzzer does not stop, return the engine control switch
back to the LOCK position and
add more DEF, and then start
over from step (2) above.
5. Turn the engine control switch to the LOCK position.
The DEF freezes at approximately
−11 °C (12 °F).
In cold weather, when the vehicle is
left without performing these actions
and the DEF tank freezes, the low
DEF level warnings and indicators
may not turn off when DEF is added
until after the tank defrosts.
Make sure to stop the engine before
adding the DEF. See Warning
Buzzers 091.
When DEF Freezes
Engine coolant circulates through
the DEF tank to thaw it when frozen
and prevent it from freezing while

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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174 Driving and Operating
the engine is running. The vehicle
can be driven normally when DEF is
frozen in the DEF tank.
If the Refill DEF warning light is on
and the remaining DEF in the DEF
tank is frozen, the vehicle low level
warning system cannot be reset by
adding DEF. The DEF gauge will not
register correctly should the
remaining DEF freeze at this level.
Move the vehicle to a location to
allow the DEF to thaw. Once the
DEF is thawed the DEF gauge
should read correctly allowing the
low level warning system to reset.
To avoid this condition follow the
instructions for Adding DEF in Cold
Weather.
{Warning
Do not warm up the DEF tank
using a burner, heater, etc. You
and others could be seriously
injured.DEF Storage
Seal the container and store it in an
indoor place with good ventilation
avoiding direct sunlight.
When storing DEF, the shelf life
varies depending on the room
temperature of the storage place.
For details, please contact the
distributor of the DEF.
For storage of DEF, seal the
container to prevent the moisture
from evaporating.
Even when DEF has been frozen,
its quality is maintained when it is
thawed. It can be used as it is.
To store or carry DEF, use the
original container in which the DEF
was kept at the time of purchase.
Also, if other containers are used,
prepare a clean container for
exclusive use, which can be a
polyethylene resin tank (PE) or
stainless steel container, and do not
introduce foreign matter such as
water or contamination. 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
DEF tank, DEF Control Unit, 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.