2020 CHEVROLET LOW CAB FORWARD light

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 159
4 START :On all engines, start is in
the position furthest clockwise. The
engine is started in this position.
Turn the key against spring
pressure to energize the starter.
When key is released, spring
pressure returns it to the ON
position. Release the key as soon
as the engine has started.
If the key cannot be turned from the
LOCK position to the ON position,
lightly move the steering wheel
clockwise and counterclockwise
while trying to turn the key.
Starting and Stopping the
Vehicle
Check around the Vehicle before
Starting the Engine
Proper care and operation will not
only extend the service life of your
vehicle but also improve fuel
economy.
Before pulling away, perform a
thorough safety check, making sure
there are no children or obstructions around the vehicle. Take off the
chocks after confirming that the
parking brake is securely applied.
Sit behind the wheel, adjust the seat
position, and buckle up the seat
belt. The passengers are also
required to buckle up the seat belts.
Adjust the positions of the steering
wheel and mirrors. Lock the doors.
Turn the power of the dome light or
accessories OFF before starting the
engine. See
Seat Position 026,
Seat Belts 031, Steering Wheel
Adjustment 053, and Mirrors021.
Keep the Floor Around the
Driver's Seat Clean and Tidy{Warning
It is extremely dangerous to have
empty cans, empty bottles or
other items rolling around on the
floor because they could get
trapped under the brake pedal
and prevent brake application.
For proper pedal operation, it is (Continued)
Warning (Continued)
also essential to lay floor mats
properly. Incorrectly installed floor
mats would hinder free movement
of the pedals.
Do not use the dashboard pocket
or the top of the dashboard as a
place to put items that could roll,
which could interfere with your
driving. You and others could be
seriously injured.
Choose Your Footwear Suitable
for Driving
{Warning
Choose footwear that ensures
proper operation of pedals when
driving the vehicle. Use of
footwear unsuitable for driving
may cause an accident.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
160 Driving and Operating
Starting the Engine
Do not keep the engine control
switch in the START position for
more than about 10 seconds.
Operating the starter for too long
might cause starter and battery
failure or may result in overheating.
When the engine does not start,
wait for 20 to 30 seconds and then
turn the engine control switch again.
Before starting the engine sit in the
driver seat, check that the parking
brake is firmly engaged, the selector
lever is in the P or N (P is preferred)
position and the shift indicator also
shows P or N, and firmly press the
brake pedal to start the engine.
When stopped on a slope, start the
engine with the selector lever in the
P position. SeeIgnition Positions
0 157.
1. Make sure that the selector lever is in the P or N position
and firmly press the brake
pedal.
2. When the engine control switch
is turned to the ON position,
the wait-to-start light comes on
and it goes out in about
1 second when the engine is
warm, to about 10 seconds
when the engine is cold.
3. After confirming that the wait-to-start light has gone out,
turn the engine control switch
to the START position to start
the engine. Release the engine
control switch as soon as the
engine starts.
4. Do not crank the engine for more than 10 seconds at a
time. If the engine does not
start, wait 20 to 30 seconds
with the engine control switch
in the LOCK or ACC position
before trying to start again. It is normal for the vacuum warning
buzzer to sound for a few seconds
after the engine has started.
After the engine has started, check
to be sure the selector lever is still
in the P position.
This engine has an automatic
warm-up system that increases
engine idle speed and applies the
exhaust brake. Allow sufficient time
to let the engine circulate lubricant
oil before driving. This usually
requires 30 seconds to 2 minutes
depending on ambient conditions.
See
Brake System Warning Light
(Parking Brake Light) 062.
The turbocharged engine should be
started in a way which ensures the
bearings supporting the rotating
parts of the turbocharger are
sufficiently lubricated. Do not race a
cold engine.
At low ambient temperatures, a cold
engine may emit more smoke than
usual.
Do not drive the truck until the
engine has had sufficient time to
circulate the lubricant oil. This

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 161
usually requires 30 seconds to
2 minutes depending on ambient
conditions. This will help reduce
white start-up smoke.
Preheating :Diesel engines are
compression ignited, which makes
them difficult to start when they are
cold because the compression
alone cannot create a temperature
high enough for fuel to ignite.
Preheating means warming the
compressed air inside the
combustion chambers to facilitate
engine starting. Be sure to start the
engine after the wait-to-start light
has gone out.
Start : Do not press the accelerator
pedal at the engine start. The
accelerator opening degree at the
engine start is electronically
controlled.
Warm-up : Do not race the engine
to speed warm-up. Cold Weather Starting
If you plan ahead for cold weather,
starting and driving your vehicle
should be no problem. The following
tips will help ensure good starting in
cold weather.
Oil gets thicker as it gets colder,
which slows down the engine
cranking speed. The diesel engine
functions by the heat of
compression (and glow plugs when
cold), rather than through the use of
spark plugs as in a gasoline engine.
So, your engine must crank faster
than a gasoline engine before it will
start.
To be sure the engine can turn fast
enough to start, use SAE 10W-40
viscosity engine oil when prevailing
temperatures drop below 0 °C
(32 °F). See the oil quality and oil
viscosity recommendations. Using
the proper viscosity oil will make
starting easier down to -23 °C
(-10 °F). When prevailing
temperatures drop below -23 °C
(-10 °F), the engine block heater
may be needed for starting. See
Engine Heater
0163. Maintenance Items to Aid Cold
Weather Starting
Since the basic principle of diesel
engine ignition is based on
compression, the diesel engine is
somewhat harder to start than a
gasoline engine when the
temperature is below freezing.
To help prevent hard starting
problems, special attention should
be given to following normal
maintenance items:
1. Neglecting to have the fuel filter and water separator
serviced can be one of the
major contributors to hard
starting. If water is permitted to
accumulate in the primary filter,
it will freeze and make starting
the engine impossible.
2. Make sure the fuel tank vent is open.
3. Always refuel at the end of a day's operation. Moisture will
condense in an empty tank;
therefore, the tank should be

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
164 Driving and Operating
3. Plug the cord into anythree-prong 110 volt outlet
(normal household current).
It may require several hours to
sufficiently heat the engine.
Outside temperature, oil
viscosity, etc., will affect how
long the block and oil pan
heater should remain plugged
in. Contact your dealer for the
conditions in your area.
4. After using the heater(s), be sure to restore the cord
properly, to help keep it away
from moving engine parts.
If the cord is too short, use a heavy
duty, three-prong extension cord. Do
not use an extension cord such as
you would use for a lamp, because
the cord may overheat.
The engine should go through a
warm-up period to warm up the
engine oil before placing engine
under load. This will ensure proper
lubrication of the engine.Engine Alarm and
Automatic Shutdown
If the system senses any of the
following conditions: high engine
temperature, low engine oil pressure
or low engine coolant, the
corresponding warning light and
engine alarm (shutdown) warning
light will come on. If the engine
alarm (shutdown) warning light
comes on, you will also hear a tone
alarm.
If your vehicle has the engine
shutdown feature, your engine will
shut down in 30 seconds. Pull safely off the road and shut off
the engine. Do not start it until the
cause of the problem is known, and
the problem is fixed. However, if the
engine shuts down when you are
still in traffic, you can restart the
engine and get another 30 seconds
of operation. Do this only if you
have to, since there is a problem
that can harm the engine if it is not
fixed. See
Engine Shutdown
Warning Light 068.
Idle Shutdown
Idle Stop is a dealer programmable
function which will automatically turn
off the engine, at idle, when specific
programmed conditions are met.
See your dealer for details. When
the Idle Stop light comes on, it alerts
you that programmed conditions
have been met and the engine is
about to shut down. This light stays
on after the engine has stopped.
This indicator light will come on
when the engine control switch is
turned to the ON position and then
should go out after approximately
3 seconds.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 165
If the idling stop function does not
initiate, a transmission related
problem may have occurred. Please
contact your dealer. (There is a
Diagnostic Trouble Code (DTC) that
inhibits the idling stop function when
the Service Transmission Warning
Light is not illuminated).
High Idle System
Use high idle mode to increase
engine idle speed to 1,200 r/min
when the vehicle is stationary.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
166 Driving and Operating
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.
4. Check that the brake low vacuum 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
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.
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

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 171
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 Driver Information
Center (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) 070,
Recommended Fluids and
Lubricants 0339, and Engine Oil
0 235.
{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 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
172 Driving and Operating
The selectable (switch) regeneration
required warning light (amber) will
turn on when regeneration cannot
be completed automatically. Perform
Running or Switch regeneration in
accordance with the proper
procedure. This is to restore DPF
function and is normal.
The exhaust pipe mixes air with the
exhaust gas to lower its temperature
before it leaves the exhaust pipe.
The frequency of regeneration
increases especially under the
following environments:
‐Midwinter.
‐ Continuous low-speed driving for
long hours (The frequency of
regeneration increases
particularly with special
equipment vehicles such as
sweeper vehicles which mainly
travel at low speed. The
frequency of regeneration is
higher as compared to delivery
vehicles which mainly travel at
standard high speed). Automatic regeneration is performed
under normal driving conditions
(DPF soot accumulation status level
5, and in rare cases, may be
performed at continuously
low-speeds for long hours, except
PM level 5); however, the
regeneration required warning light
(amber) may be displayed in the
DIC under the following driving
conditions:
‐
When only low-speed driving at/
under vehicle speed of 15 km/h
(9 MPH) is performed.
‐ When frequent engine start and
stop are performed.
‐ When the engine stops every
time before the engine is
warmed up.
‐ When continuous idling (over
1 hour) is frequently performed.
If the vehicle is stationary with the
engine idling during DPF
regeneration, the exhaust brake or
exhaust throttle operates. Operating
sounds will be heard when the exhaust brake or exhaust throttle is
activated or deactivated. The
sounds do not indicate a fault.
White smoke could be emitted
briefly from the exhaust pipe in the
following situations, but it is not
indicating a fault.
‐
Combustion of PM during DPF
regeneration.
‐ During DPF regeneration of a
new vehicle which has been
driven a certain distance. The
vehicle may not emit white
smoke during its initial operation
when new.
‐ Long continuous idling.
The exhaust brake may
automatically be activated in order
to prevent emission of white smoke
if the engine idles continuously over
an extended period of time.
White smoke may be produced
during switch regeneration; do not
perform switch regeneration in any
poorly ventilated indoor place.