coolant temperature CHEVROLET LOW CAB FORWARD 2020 User Guide

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
170 Driving and Operating
{Warning
Breathing diesel engine exhaust
exposes you to chemicals known
to the State of California to cause
cancer and birth defects or other
reproductive harm.. Always start and operate
the engine in a
well-ventilated area.
. If in an enclosed area, vent
the exhaust to the outside.
. Do not modify or tamper
with the exhaust system.
. Do not idle the engine
except as necessary. For
more information go to
www.P65warnings.ca.gov/
diesel.
See California Proposition
65 Warning 0230 and the back
cover.
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
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 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 175
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
70.
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 70.
While the vehicle is at a stop with
engine idling, the engine speed
increases.

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 177
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)
070.
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 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
180 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 Messages074.
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 70.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 74
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 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 183
{Warning
On occasion, you may notice an
odor when the DEF tank is
opened. Do not sniff the filler
port, etc.
When refilling the DEF tank:
Failure to follow the above
instructions could result in a fire
or a breakdown of the selective
catalytic reduction (SCR) system.
Do not dilute DEF with water.
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(Continued)
Caution (Continued)
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.

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
184 Driving and Operating
5. Turn the engine control switchto 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 079.
When DEF Freezes
Engine coolant circulates through
the DEF tank to thaw it when frozen
and prevent it from freezing while
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.

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
Vehicle Care 243
.Dipstick H (HOT) —
Transmission fluid
temperature Approx. 70 -
80 °C (158 - 176 °F).
. The “C (COLD)” range on
the dipstick is a guide used
by your dealer for
specialized equipment used
to replace or service the
automatic transmission
fluid. When performing your
own inspections, always
use the “H (HOT)” range
after warming up the
vehicle.
The fluid must be hot to
ensure an accurate check.
The fluid level rises as
temperature increases.
6. If the fluid level is too low, add the specified fluid through the
dipstick guide tube. Also, check
whether there are no fluid
leaks.
7. Insert the dipstick securely into position.{Warning
Be extremely careful not to burn
yourself when checking the oil
level if the engine temperature is
high. Protect yourself with
gloves etc.
You and others could be seriously
injured.
Discarded parts, oil, grease and
fluids could have an adverse effect
on the environment. It is difficult to
dispose of these, so have your
dealer handle all checks and
replacements.
Engine Air Cleaner/Filter
Air Cleaner
Using a clogged air cleaner element
not only reduces engine output but
also causes increased fuel
consumption and an increased DPF
regeneration frequency. Be sure to use a genuine air cleaner
element. If a different air cleaner
element is used, it may cause the
sensor to output a wrong signal.
See
Maintenance Schedule 0317.
Air Cleaner Indicator Light
When the air cleaner indicator light
comes on, check the air cleaner
element. If the air cleaner element is
clogged, replace the air cleaner
element.
See Vehicle Messages 074.
See Maintenance Schedule 0317.
Engine Coolant
Protection of Engine Against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.

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
Vehicle Care 245
Warning (Continued)
eyes are still irritated or otherwise
feel abnormal, seek immediate
medical attention.
If the engine coolant gets on your
skin, rinse it off using a soap with
a large amount of water. Also,
if abnormality is seen, seek
medical attention.
Engine coolant is flammable, and
therefore, it must be kept away
from flames and other heat
sources. Engine coolant also
could ignite if it comes in contact
with a hot surface, such as the
exhaust manifold. Exercise
caution to prevent this from
happening.
You and others could be seriously
injured.
Preparing Engine Coolant
To prevent engine damage due to
freezing of the engine coolant and
to protect the cooling system from corrosion, use a mixture of the
recommended type antifreeze and
water. If the engine of the vehicle is
at
−30 °C (−22 °F) or above, the
coolant concentration should be
50%. Direct use of “50/50
Pre-diluted” product which is already
diluted to 50% concentration is
recommended. If the outside
temperature engine or vehicle is
used at −30 °C (−22 °F) or below,
coolant concentration of 55% is
recommended.
It is the owner ’s responsibility to:
. Maintain the engine cooling
system freeze protection at or
above −30 °C (−22 °F) (at or
below −30 °C (−22 °F) in colder
climates to ensure protection
against corrosion and loss of
engine coolant from boiling.
A 50/50 (55/45 for colder
climates) mixture of the
recommended type antifreeze
and water will provide freeze
protection to at or above −30 °C
(−22 °F), (at or below −30 °C
(−22 °F) in colder climates) and
boil protection to 128 °C (262 °F). Periodic replacement
of engine coolant is needed to
replenish the anticorrosion
additives that wear out with use.
Engine coolant that has become
dark in color shows that it needs
to be changed.
. Use only the recommended
coolant. See Recommended
Fluids and Lubricants 0339.
. Do not use methanol-base
antifreeze, alcohol or plain water
alone in your vehicle at any time.
They will boil at a lower point
than that at which the engine
coolant temperature gauge will
warn of overheating, and they do
not provide proper protection
against corrosion.
Engine Coolant Quantity
For the quantity of engine coolant,
see Capacities and Specifications
0 349. After changing the engine
coolant, check that the engine
coolant is up to the specified level.

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
248 Vehicle Care
1. When the engine is cool,remove the radiator cap (1).
.Turn the cap slowly to the
left until it reaches a “stop”.
Do not press down while
turning the cap.
. Wait until any remaining
pressure (indicated by a
hissing sound) is relieved,
then press down on the cap
and continue turning it to
the left.
2. Fill the radiator to the base of the filler neck (2) and install the
radiator cap. Add enough engine coolant to provide for
required cooling, freezing, and
corrosion protection.
3. Run the engine until the engine coolant temperature rises to
normal level, and idle the
engine for 10 minutes.
4. Install the radiator cap.
Check, replenish or change the
engine coolant only after the engine
has sufficiently cooled down.
When the engine is still hot, take
care to prevent engine coolant from
contact with the exhaust manifold.
Any such contact could result in
exhaust manifold damage.
If you use the proper quality engine
coolant, there is no need to add
extra inhibitors or additives which
claim to improve the system. They
may be harmful to the proper
operation of the system.
Do not overfill the engine coolant
reserve tank.
If the level of engine coolant
changes rapidly, have your vehicle
inspected at your dealer. Thermostat
The engine coolant temperature is
controlled by thermostat(s). The
thermostats stop engine coolant
flow through the radiator until a
preset temperature is reached. The
thermostats are installed in the
engine coolant outlet on the engine
block. The same thermostats are
used in both winter and summer.
When a replacement is needed,
genuine GM parts are
recommended.
Radiator Pressure Cap
The radiator cap, a 108 kPa (16 psi)
pressure type, must be installed
tightly, otherwise engine coolant
may be lost and damage to the
engine may result from overheating.
The radiator pressure cap should be
checked periodically for proper
operation. If a replacement is
required, a genuine GM part is
recommended.

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
Vehicle Care 249
Engine Overheating
When the Engine Overheats
The engine cooling system may
overheat if the engine coolant level
is too low, if there is a sudden loss
of engine coolant (such as radiator
hose failure), or if other problems
occur. It may also temporarily
overheat during severe operating
conditions such as:
.Climbing a long hill on a hot day.
. Stopping after high-speed
driving.
. Idling for long periods in traffic.
If engine power drops and the
needle on the engine coolant
temperature gauge goes up above
the upper limit of the safety zone
and enters the "H" zone, the engine
is overheating. The engine overheat
warning light will come on and the
warning buzzer will sound. Either
steam or boiling engine coolant will
squirt out of the radiator. The
vehicle will also have an “OVERHEAT”
message displayed. Take the
following corrective actions
immediately.{Warning
To help avoid being burned:
Do not tilt the cab or open the
engine access cover if you see or
hear steam or engine coolant
escaping from the engine
compartment. Wait until no steam
or engine coolant can be seen or
heard before tilting the cab or
opening the engine cover.
Do not remove the radiator cap or
engine coolant reserve tank cap if
the engine coolant in the tank is
boiling. Also do not remove the
radiator cap while the engine and
radiator are still hot. Scalding fluid
and steam can be blown out
under pressure if either cap is
taken off too soon.
You and others could be seriously
injured. If Steam Is Coming from the
Engine Compartment
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have other
reasons to suspect the engine
may be overheating, continued
operation of the engine (other
than as described here) even for
a short period of time may cause
a fire and the result in personal
injury and severe vehicle
damage. Take immediate action
as outlined.
You and others could be seriously
injured.
If you see or hear escaping steam
or have any other reason to suspect
there is a serious overheat
condition, stop and park the vehicle
as soon as it is safe to do so, turn
on the hazard warning flasher and
then turn off the engine immediately
and safely exit the vehicle.