Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Driving and Operating 175
Activating High Idle Mode
Follow the below procedure to
activate the high idle mode:1. Set the parking brake.
2. Set the selector lever in P (Park) or N (Neutral) position.
3. Do not press the brake pedal. 4. Press the cruise control main
switch to set it to ON. At this
time, the operation indicating
light will turn to green.
5. Turn and hold the cruise control set switch in the SET
position. After approximately
3 seconds the cruise control
set indicator light will begin to
flash slowly and the engine idle
will increase to 1,200 r/min.
Canceling High Idle Mode
Any of the following actions will
cancel high idle mode.
. The cruise control main switch is
set to OFF.
. The brake pedal is pressed.
. The parking brake is released.
. The selector lever is moved from
P (Park) or N (Neutral) position.
. The accelerator pedal is
pressed, accelerating the engine
beyond the engine speed
threshold.
The cruise set indicator light will
stop flashing and the engine speed
will return to normal.
Engine Checks Before
Operating
Checks Before Operating
Allow the engine to warm up before
placing the engine under heavy load
driving. While the engine is warming
up under light load, the following
checks should be made:
1. Observe the red engine oil pressure warning light. The
light should go out when the
engine is running. If it stays on,
shut the engine off and find the
cause.
2. Look at the engine coolant temperature gauge. If the
gauge reaches the H (HOT)
area, stop the engine and find
the cause of the overheating.
3. Check that the battery warning light has gone out. The light
should go off and stay off at
normal idle speeds. If the light
does not go out or comes on
during normal operation, have
the charging system checked.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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176 Driving and Operating
4. Check that the brake lowvacuum warning light is out
and that the vacuum buzzer is
not sounding. It is normal for
the warning buzzer to sound
for a few seconds after the
engine starts. If the light and
buzzer remain on, do not drive
the vehicle until the cause has
been found and corrected.
5. Look at the brake system warning light. It should be out
when the parking brake is
released and the engine is
running. If it stays on, it could
mean that the brake fluid level
is low. Check the brake fluid
reservoir. This condition must
be corrected before moving the
vehicle.
{Warning
To reduce the chance of personal
injury and/or vehicle damage due
to engine overheating, never
leave the engine idling without an
alert driver present. If the engine
(Continued)
Warning (Continued)
should overheat, as indicated by
the engine coolant temperature
gauge, immediate action is
required to correct the condition.
Continued operation of the
engine, even for a short time, may
result in a fire.
For vehicles with a diesel engine,
do not engage the exhaust brake
while the engine is idling as this
may cause engine overheating.
You and others could be seriously
injured.
Avoid Unnecessary Idling of the
Diesel Engine
If the diesel engine idles too long,
the engine coolant temperature will
fall below the operating range. Low
engine operating temperature
causes several conditions that are
harmful to engine operation and life.
Incomplete combustion of fuel in an
engine that is not fully warmed-up
causes crankcase dilution and
forms lacquer and gummy deposits on valves, pistons, and rings. It also
causes rapid accumulation of
sludge within the engine.
Parking over Things
That Burn
{Warning
Exhaust parts and gases become
very hot when the DPF is being
regenerated.
Parking over flammable items
could allow them to touch hot
exhaust parts under your vehicle
and cause them to ignite. Do not
park over papers, leaves, grass
or other things that can burn. You
and others could be seriously
injured.
Keep Flammable Material Away
from the Vehicle
The exhaust pipe is extremely hot
immediately after vehicle operation.
Before parking, make sure the area
is free of flammable material (for
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
180 Driving and Operating
Diesel Particulate
Filter
Diesel Particulate Filter (DPF)
The DPF purifies diesel exhaust
gases of particulate matter (PM). PM
is filtered from the exhaust gas and
collected in the DPF. When PM is
collected to the predetermined level
by the engine control module, the
DPF automatically burns the PM in
a process called regeneration.
Regeneration may not be completed
under certain driving conditions.
If this occurs, the multi-information
display (DIC) will provide prompts to
properly complete DPF
regeneration.
The following sections will provide
details on DPF regeneration. Follow
the steps carefully to keep the DPF
in good working order. SeeDriver
Information Center (DIC) (Diesel
Only) 093, Recommended Fluids
and Lubricants 0378, and Engine
Oil (Gasoline) 0257 orEngine Oil
(Diesel) 0251.
{Warning
Exhaust parts and gases become
very hot when the DPF is being
regenerated.
Parking over flammable items
could allow them to touch hot
exhaust parts under your vehicle
and cause them to ignite. Do not
park over papers, leaves, grass
or other things that can burn. You
and others could be seriously
injured.
This content is to restore the
function of the DPF and it is not a
malfunction. However, the check
engine malfunction indicator light
and reduced engine power indicator
light may come on and the power
output may be limited if driving or
power take-off (PTO) operation is
continued for a long time with the
regeneration required warning light
or selectable (switch) regeneration
required warning light (amber/
red) on. This is to prevent the DPF from
being damaged. When operating
PTO during parking, check to
ensure that the regeneration
required warning light or selectable
(switch) regeneration required
warning light (amber/red) on the DIC
is not on.
Engine oil that supports DPF (low
ash oil) is recommended. Use of low
ash oil extends the maintenance
interval of the DPF filter.
Do not modify the DPF or exhaust
pipe. Changing the alignment,
length or diameter of the exhaust
pipe would adversely affect the
exhaust system's exhaust emission
reduction function. If any
modification is necessary to install a
component to the rear of the
vehicle, consult your dealer.
Although the DPF filter automatically
undergoes regeneration (burning of
the accumulated PM) when a
certain amount of PM has
accumulated, driving conditions can
prevent completion of regeneration.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 183
{Warning
To prevent fire, ensure that there
is no combustible material near
the muffler, the DPF or the
exhaust pipe. Also, be careful not
to burn yourself on the hot
exhaust gas. You and others
could be seriously injured.
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 Switch
The 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.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
184 Driving and Operating
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
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 redRegeneration 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 light
or 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)
(Diesel Only)
093.
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)
(Diesel Only) 093.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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186 Driving and Operating
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.
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)
(Diesel Only)093.
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.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
188 Driving and Operating
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.-
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Driving and Operating 189
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 Messages (Diesel Only)
097.
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)
(Diesel Only) 093.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
(Diesel Only) 097
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.