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
Driving and Operating 179
Warning (Continued)
or corroded exhaust system or
cab. Do not run the engine in
confined areas (such as garages,
next to a building or near another
stopped vehicles with engine
running) any more than needed to
move the vehicle.
When the vehicle has to be
stopped in an unconfined area
with the engine running for any
more than a few minutes, take the
following steps:. Adjust the heating or cooling
system to force outside air
into the cab.
. With temperature and outlet
selector knob in any
position:
. Set the air selector lever to
the fresh air position.
. Set the fan speed control
knob to the maximum speed
position.
(Continued)
Warning (Continued)
.Keep the exhaust tailpipe
area clear of snow and
other material to help
reduce the buildup of
exhaust gases under the
vehicle.
This is particularly important when
parked in blizzard conditions. You
and others could be seriously
injured.
See Climate Control Systems 0126
and Maintenance Schedule 0345.
Running the Vehicle
While Parked
Caution
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)
Caution (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. Do not engage the
exhaust brake while the engine is
idling as this may cause engine
overheating.
Avoid Unnecessary Idling of the
Diesel Engine
If the 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.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
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.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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206 Driving and Operating
Warning (Continued)
When you move the selector lever
into D, 2, 1 or R (diesel engine),
or D6, D4, 2, 1, or R (gasoline
engine), creep will cause the
vehicle to move.
When pulling away from a
standstill, you must control the
speed using only the accelerator
pedal. Operate the accelerator
pedal carefully.
Do not operate the selector lever
while pressing the accelerator
pedal. The vehicle may make a
sudden start, possibly causing an
accident.
For gasoline vehicles, do not
drive the vehicle with the
transmission in neutral. Not only
will the engine brake not function,
but the transmission will also be
damaged.
You and others could be seriously
injured.When pulling away, visually check
the position of the selector lever.
If you always press the push button
while operating the selector lever,
the lever may occasionally move to
the other gear position against your
intentions.
Practice operating the selector lever
between the N and D (diesel engine)
or D6/D4 (gasoline engine) without
pressing the push button.
Do not operate the selector lever
while pressing the accelerator
pedal. Doing so is dangerous
because the vehicle would
suddenly move.
Do not operate the automatic
transmission at or near stall
condition for more than
five seconds. Stall condition is when
the transmission is in one of the
driving ranges, the engine is running
at high speed, but the drive wheels
are unable to move. This condition
might occur if the vehicle is stuck in
deep sand or is pushing against a
fixed barrier. Operating the
transmission at stall condition will
result in overheating and damage. Do not hold your vehicle on an
upgrade with the accelerator pedal.
Doing so will result in automatic
transmission overheating and
damage. Use the parking brake or
foot brake to hold the vehicle on an
upgrade.
Even if you plan to move only a
short distance, sit in the correct
driving position and make sure you
can firmly press the brake and
accelerator pedals.
When you reverse, you twist to look
rearward so pedal operation
becomes difficult. Firmly press the
brake pedal. Also, practice returning
the selector lever immediately to the
N position after reversing. When
pulling away, visually check the
selector lever position and the shift
indicator.
When the vehicle is stopped, do not
keep pressing the accelerator pedal
with the selector lever in a forward
gear or R position while pressing
the brake pedal. Doing so may
cause a breakdown.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Driving and Operating 209
Driving conditionsSelector lever position
Normal uphill road Diesel engine
–D (overdrive off
switch ON)
Gasoline engine –D4
Steep uphill, steep slope, mountain
road with many sharp curves 2 or 1
Long uphill road 2
Downhill driving:
Do not overuse the foot brake. This
will cause the brakes to overheat,
reducing their effectiveness. On
long downward slopes or sharp
downhill sections of road, use the
engine brake together with the foot
brakes to control the speed.
On vehicles with a diesel engine,
when the selector lever is in the D
position, you can drive with the
overdrive off switch ON to allow a
gentle engine brake to be applied.
On vehicles with a 3.0L diesel
engine, push the overdrive off
switch to the ON position at speeds below 135 km/h (84 MPH) to
increase engine braking action
when traveling downgrade.
On vehicles with a 5.2L diesel
engine, push the overdrive off
switch to the ON position at speeds
below 101 km/h (63 MPH) to
increase engine braking action
when traveling downgrade.
On vehicles with a gasoline engine,
with the selector lever in the D4
position at speeds below
121 km/h (75 MPH) to increase
engine braking action when
traveling downgrade.
You can increase engine braking by
driving with the selector lever in the
2 position.To apply a stronger engine brake on
sharp downhill sections, shift the
selector lever to the 1 position when
required.
See
Control of a Vehicle 0133.
Driving at Low Speeds for
Sustained Periods
On vehicles with a 3.0L diesel
engine, any low speed applications
such as sweeper, road marking
machinery, trash collectors, highway
striping or moving, etc. require the
following treatment to prevent the
automatic transmission fluid (ATF)
from overheating:
Select 1 position during low speed
operation under 28 km/h (17 MPH).
Select 2 position during low speed
operation under 53 km/h (33 MPH).
On vehicles with a 5.2L diesel
engine, any low speed applications
such as sweeper, road marking
machinery, trash collectors, highway
striping or moving, etc. require the
following treatment to prevent the
automatic transmission fluid (ATF)
from overheating:
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
210 Driving and Operating
Select 1 position during low speed
operation under 18 km/h (11 MPH).
Select 2 position during low speed
operation under 36 km/h (22 MPH).
On vehicles with a gasoline engine,
any low speed applications such as
sweeper, road marking machinery,
trash collectors, highway striping or
moving, etc. require the following
treatment to prevent the automatic
transmission fluid (ATF) from
overheating:
Select 1 position during low speed
operation under 36 km/h (22 MPH).
Select 2 position during low speed
operation under 61 km/h (38 MPH).
SeeAutomatic Transmission Fluid
Temperature Warning Light 088.
To Stop Your Vehicle 1. To temporarily stop the vehicle, press the brake pedal firmly
while the selector lever is in
D (diesel engine) or D6/
D4 (gasoline engine). 2. Use the parking brake as
required. Press the brake pedal
firmly, and firmly apply the
parking brake.
If the vehicle is stationary for a
long time, move the selector
lever into the N or P position.
If the selector lever is kept in
D (diesel engine) or D6/
D4 (gasoline engine), the
temperature of the automatic
transmission fluid increases
due to heat from the torque
converter.
To ensure reliable brake application,
be sure to use your right foot to
press the brake pedal.
When leaving the driver's seat,
follow the When Parking Your
Vehicle procedure.
To Start After Stopping
To start again after stopping your
vehicle, visually check that the
selector lever is in D (diesel engine)
or D6/D4 (gasoline engine), and
gradually press the accelerator
pedal to pull away. When Parking Your Vehicle
{Warning
Do not leave your vehicle while
the engine is still running. Do not
park with the selector lever in a
position other than P or N the
vehicle may begin moving by
itself due to creeping. You may
accidentally press the accelerator
pedal when getting into the
vehicle causing it to start moving
suddenly.
When parking the vehicle, always
apply the parking brake and move
the selector lever to the P
position.
When parking on a slope, move
the selector lever in the P position
and block the wheels with chocks.
You and others could be seriously
injured.
1. Keep pressing the brake pedal firmly with your right foot, then
apply the parking brake.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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234 Driving and Operating
Caution
Do not use blends containing
more than 20% biodiesel. Any
engine, fuel system, or exhaust
after-treatment system damage
would not be covered by the
vehicle warranty.
As a renewable fuel, biodiesel
provides some environmental
benefits. However, biodiesel has
unique properties and needs to be
handled differently than diesel fuel.
Its use presents additional risks and
may not be appropriate in all
situations. Certain vehicle operating
modes increase these risks and
should be avoided. Read further to
determine if your driving habits are
compatible with the use of biodiesel.
Biodiesel fuel quality degrades with
time and exposure to high
temperature quicker than Ultra Low
Sulfur Diesel fuel. More frequent
refueling provides the best
opportunity to have a supply of fresh fuel. Storage at hot ambient
temperatures will accelerate
biodiesel degradation.
Owners who use very little fuel,
or who have vehicles or fuel stored
for extended periods of time, should
avoid the use of biodiesel blended
fuels above 5% by volume. When
vehicles are stored for longer than
one month, they should be run out
of biodiesel to below one-quarter
tank, refueled with Ultra Low Sulfur
Diesel fuel, and driven several miles
before storage.
At temperatures below 0 °C (32 °F),
it is recommended to switch to Ultra
Low Sulfur Diesel fuel with no
biodiesel content, or to blends with
biodiesel containing less than 5% by
volume. At these extreme cold
temperatures, biodiesel blends
higher than 5% by volume may
cause fuel filter plugging and
system gelling, which can lead to
vehicle operability problems.
Fuels improperly blended for cold
temperature operation may result in
restricted fuel filters and degraded
vehicle performance. The vehicle is
equipped with a fuel heating system
to provide a level of protection
against filter plugging from gelling or
waxing of conventional diesel fuel
and biodiesel blends. If the
operating temperature is far below
the temperature at which gelling or
waxing of the fuel occurs, the
system will not prevent all cases of
filter plugging.
If the vehicle experiences a fuel
filter restriction, the on-board
monitoring system will alert the
driver that the fuel filter requires
service. The fuel filter, however, will
not prevent all damage caused by
poor quality biodiesel.
Biodiesel Blends
Use biodiesel blends that meet the
ASTM specification D6751.
Retail pumps dispensing blends
containing up to 5% biodiesel (B5)
are not required to be labeled with
the concentration of biodiesel.
Blends up to B5 must meet ASTM