coolant temperature CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

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
52 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . . 53
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Windshield Wiper/Washer . . . . . . 54
Power Outlets . . . . . . . . . . . . . . . . . 55
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . 56
Instrument Cluster . . . . . . . . . . . . . 57
Speedometer . . . . . . . . . . . . . . . . . . 58
Odometer . . . . . . . . . . . . . . . . . . . . . . 58
Trip Odometer . . . . . . . . . . . . . . . . . 58
Tachometer . . . . . . . . . . . . . . . . . . . . 59
Fuel Gauge . . . . . . . . . . . . . . . . . . . . 59
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . . . 60
Diesel Exhaust Fluid (DEF) Gauge . . . . . . . . . . . . . . . . . . . . . . . . 60
Seat Belt Reminders . . . . . . . . . . . 60
Battery Warning Light . . . . . . . . . . 61
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . . 61
Service Vehicle Soon Light . . . . 62 Brake System Warning Light
(Parking Brake Light) . . . . . . . . . 62
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . 64
Exhaust Brake Light . . . . . . . . . . . 65
Service Transmission Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . 65
Automatic Transmission Fluid Temperature Warning Light . . . 66
Overdrive Off Light . . . . . . . . . . . . . 66
Wait-to-Start Light . . . . . . . . . . . . . 67
Engine Oil Pressure Light . . . . . . 67
Engine Oil Level Indicator Light . . . . . . . . . . . . . . . . . . . . . . . . . 67
Diesel Exhaust Fluid (DEF) Warning Light . . . . . . . . . . . . . . . . 68
Engine Shutdown Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . 68
Idle Shutdown Light . . . . . . . . . . . . 68
Reduced Engine Power Light . . . . . . . . . . . . . . . . . . . . . . . . . 69
High-Beam On Light . . . . . . . . . . . 69
Daytime Running Lamps (DRL) Indicator Light . . . . . . . . . . . . . . . . 69
Cruise Control Light . . . . . . . . . . . 70
Information Displays
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . 70
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . 74
Warning Buzzers . . . . . . . . . . . . . . 79

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
60 Instruments and Controls
Engine Coolant
Temperature Gauge
With the engine control switch in the
ON position, this gauge indicates
the temperature of the engine
coolant.“C”means cold while “H”
means hot. During operation, the
needle should stay in the safety
zone. See Engine Overheating
0 249.
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have any other
reason to suspect the engine may
be overheating, continued
operation of the engine, even for
a short time, may result in a fire
and the risk of personal injury and
severe vehicle damage. Take
immediate action as outlined in
Engine Overheating. See Engine
Overheating 0249.
Caution
If the needle goes up above the
upper limit and enters the H zone,
the engine is likely to overheat.
Immediately pull safely off the
road out of the way of traffic and
take the necessary actions to
deal with engine overheating.
If the needle nears the H zone but
(Continued)
Caution (Continued)
does not cross into it, this is not a
problem, but check the engine
coolant level in the reservoir. Add
engine coolant as necessary.
See “Engine Overheat Warning
Light” under Driver Information
Center (DIC) 070 and
Engine Coolant 0243.
Diesel Exhaust Fluid
(DEF) Gauge
The DEF gauge is part of the Driver
Information Center (DIC). See
Driver Information Center (DIC)
070.
Seat Belt Reminders
Seat Belt Warning Light
There is a driver seat belt reminder
light on the instrument cluster.

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
74 Instruments and Controls
Vehicle speed will be severely
limited when the DEF tank is empty.
Be sure to add DEF in advance of
the empty status. SeeDiesel
Exhaust Fluid 0180.Vehicle Messages
The Driver Information Center (DIC)
will display warnings, messages,
and other operation-related
information to alert of system
failures or other necessary checks
that should be performed. Use the
DIC selector to choose the desired
screen page or function.
Engine Overheat Warning
Light
OVERHEAT
This message displays and a
warning light appears when the
engine has overheated and the
engine coolant temperature gauge
needle reaches the red zone. At the
same time a buzzer sounds.
Immediately pull off to a safe place
to take the necessary actions and
check the vehicle. Do not shut down
an overheating engine immediately.
Otherwise, the engine may seize
up. Take appropriate actions for
engine overheating. This light will also activate the
engine alarm and automatic
shutdown system, if equipped.
See
Engine Alarm and Automatic
Shutdown 0164, Engine
Overheating 0249, Engine Coolant
0 243, and Engine Coolant
Temperature Gauge 060.
{Warning
When the engine coolant is still
hot, do not remove the radiator
cap. Hot vapor will come out and
you may be scalded. Add engine
coolant only when the engine
coolant temperature has dropped.
If this light comes on and stays on
while you are driving, your engine
coolant might have overheated
and your engine may be too hot.
You should pull off the road, stop
your vehicle and take appropriate
actions for engine overheating.

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
122 Climate Controls
O:Use this position to prevent
dusty or otherwise contaminated
outside air from entering the cab,
such as in a tunnel or in congested
traffic.
Extended use of the inside air
recirculation position causes the
windshield and windows to fog up
easily, making visibility poor. For
good ventilation, switch to outside
air as soon as possible.
Temperature Control Knob : Use
this knob to select the preferred cab
interior temperature. Turn the knob
counterclockwise to lower the outlet
air temperature and clockwise to
raise it.
Fan Speed Control Knob : The fan
speed can be adjusted to any of the
four speeds available.
Air Conditioning (A/C) Switch :
Press this switch to use the air
conditioning system. The indicator
light inside the switch will come on
to show that the air conditioning
system is in operation. The air
conditioning system can also be
used for dehumidifying while the heater is being used. To turn off the
air conditioning, push this switch in
again.
When the defrost mode is selected,
the air conditioner compressor will
be on.
Even if the A/C switch is turned on,
the air conditioning system will not
operate when the fan speed control
knob is placed in the stop position.
Make sure that the fan speed
control knob is in a position other
than the stop position.
Even in seasons when the air
conditioning system is not used,
occasionally operate the system for
a few minutes with the engine
running at a low speed in order to
keep the system's components
lubricated.
Ventilation
Outside Air Ventilation :
Press the
A/C switch to the off position. Turn
the outlet selector knob to the
preferred position. Move the air
selector lever to the
Pposition. Set the temperature control knob to
the desired position. Adjust the fan
speed control knob to the preferred
speed.
How to Use the Heater
Normal Heating :
Set the outlet
selector knob to the
6or-
position. Use the-position for
warming your feet while defogging
the windshield.
Set the air selector lever to the
P
position. Adjust the temperature
control knob and the fan speed
control knob to the desired
positions.
To dehumidify the cab interior while
heating, press the A/C switch to the
on position.
As the heater uses the heat from
the engine coolant, its heating effect
is weak when the engine coolant
temperature is 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
132 Driving and Operating
Warning (Continued)
indicator lights and other
electrical circuitry would
completely stop working.
Placing the engine control switch
in the "LOCK" position while
driving would be extremely
dangerous because the key could
come out, causing the steering
wheel to lock so that you could
not turn it.
You and others could be seriously
injured.
Avoid Unnecessary Idling of
the 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 depositson valves, pistons, and rings. It also
causes rapid accumulation of
sludge within the engine.
Driving at Night
Nighttime driving is more dangerous
than daytime driving because the
field of view is narrower. Keep your
speed down, and maintain an ample
headway distance.
Metallic Plinking Sound from
the Muffler
Immediately after stopping the
engine, you may hear a metallic
plinking sound from the muffler. This
sound occurs as the muffler cools
down and contracts. It does not
indicate an abnormality or
breakdown.
When the Silencer and
Exhaust Pipe are Hot
{Warning
When the engine is running and
immediately after vehicle
operation, the DPF, silencer, and
exhaust pipe are extremely hot.
Be careful not to inadvertently
touch them when working near
them (for example, tilting the cab
or operating an attachment). You
and others could be seriously
injured.
Recommendations for Driving
in Hot Regions
The engine is more likely to
overheat in an environment where
the ambient temperature is high. To
prevent the engine from
overheating, pay attention to the
following points:
.
If the engine does not contain
the appropriate concentration of
engine coolant, overheating is
likely to occur.

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 137
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. Do not engage the
exhaust brake while the engine is
idling as this may cause engine
overheating.
The diesel particulate filter (DPF)
may automatically start
regeneration when the vehicle is
stopped and parked with the
engine running. To prevent a fire,
make sure there is no flammable
material near the muffler, DPF,
and exhaust pipe. Be careful not
to get burned by hot exhaust
gases.
You and others could be seriously
injured.Do Not Forget to Release the
Parking Brake
Pulling away with the parking brake
still applied can damage the brake
system.
Before pulling away, make sure the
parking brake is not set by checking
that the parking brake indicator light
is not on.
Be Sure to Have the Engine
Running When the Vehicle is
Moving
{Warning
When the engine is not running,
the power steering system does
not work so the steering wheel is
hard to turn. Also, the brake
booster does not work so there is
little braking ability. If you coast
down a slope without the engine
running, you would not be able to
properly control the vehicle and
could have a crash.
Parking, or Leaving
Driver
’s Seat
{Danger
It can be dangerous to get out of
your vehicle if the selector lever is
not fully in "P" (Park) or the
parking brake is not applied all
the way. Your vehicle can roll or
move suddenly.
To be sure your vehicle will not
move, even when you are parking
on level ground, follow the steps
below. (If you have to park on a
hill, also turn your front wheels so
the vehicle will roll away from
traffic.)
You and others could be seriously
injured or killed.
1. Hold the regular brake pedal down with your right foot and
apply the parking brake all the
way before shifting the
transmission. Follow the
Parking Brake instructions in
this manual for your vehicle.

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
162 Driving and Operating
filled before leaving the vehicle
standing for an extended
period.
Do not use starting aids in the air
intake system. Such aids can cause
immediate engine damage. See
Fuel for Diesel Engines 0218.
Stopping the Engine
When stopping the engine, take the
following steps: 1. Bring the vehicle to a complete stop.
2. Firmly apply the parking brake.
3. Move the selector lever to the P position and make sure that
the shift indicator shows P.
4. Allow the engine to idle for approximately 3 minutes.
5. Turn the engine control switch to the ACC or LOCK position.
Do not shut down the engine
immediately after driving the vehicle.
Otherwise, a seizure or other
failures may result. To prevent the battery from going
dead, turn the engine control switch
to the ACC or LOCK position after
stopping the engine. If you leave the
vehicle for an extended period of
time, place the engine control switch
in the LOCK position.
Let the engine idle for 3 minutes
before shutting off the engine. This
allows the turbocharger to slow
down while keeping the bearings
lubricated.
If the Vehicle Has Not Been Used
for a Long Period
If a diesel vehicle has been
standing for an extended period of
time, the turbocharger bearings
should be pre-lubricated prior to
starting. See your authorized dealer
for more detailed information.
Before using a vehicle that has not
been driven for a long period, check
the engine and transmission for oil
leakage, and make sure the oil is at
the required levels. If there is
insufficient oil, it will not adequately
reach and lubricate components,
and a breakdown will result.Start the engine and allow it to idle
for at least five minutes. Check for
abnormal noises.
For instructions on warming up the
engine, refer to
“Starting the Engine”
previously in this section.
If one year has passed since the
diesel exhaust fluid (DEF) in the
DEF tank was added, the DEF in
the tank should be replaced. Be
careful not to inhale the ammonia
odor when replacing the DEF. Also,
please contact your nearest dealer
about the replacement work.
Operating Temperature
Recommendations for Warming
Up the Engine
The engine is sufficiently warmed
up when the needle of the engine
coolant temperature gauge starts
to move.
Do not race the engine or quickly
accelerate before the engine has
sufficiently warmed up. Oil would
not have adequately reached and
lubricated components, and a
breakdown may result.

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 163
The exhaust pipe becomes
extremely hot while the engine is
idling. Before warming up the
engine, make sure there is no
flammable material, such as grass,
waste paper, oil, or old tires near the
exhaust pipe.
Engine Warm-up System
During cold ambient conditions, the
automatic engine warm-up system
operates to reduce engine warm-up
time during idling.
Automatic Engine Warm-up :
When the engine is idling with the
engine coolant temperature below
62 °C (144 °F), the engine warm-up
system automatically closes the
exhaust brake and increases engine
idle speed so that the engine is
warmed more quickly. Warm-up is
cancelled when the accelerator
pedal is pressed, and resumed
when the pedal is released.
Warm-up is automatically cancelled
entirely after the engine coolant
temperature rises above 65 °C
(149 °F).Winter Cover
.Do not cover the front of the
radiator with newspapers,
cardboard or any other
flammable material to raise the
engine coolant temperature.
. If you allow the engine to warm
up but the engine coolant
temperature does not rise, have
the nearest dealer inspect the
thermostat.
Radiator Grille Covers
{Warning
Radiator shutters, winter fronts,
or grille covers are not to be used
and may cause the engine's
radiator cooling fan to fatigue
from the alternate unloading and
loading of the blades as they
pass by the masked area
followed by the unmasked area.
After the fan has been fatigued, it
may suddenly break apart while
rotating, possibly causing (Continued)
Warning (Continued)
personal injury to anyone
standing nearby, and equipment
damage. You and others could be
seriously injured.
Engine Heater
Engine Block and Oil Pan Heater
If the vehicle is parked in a garage,
the block and pan heaters should
not be needed until the garage
temperature drops below −23°C
(−10°F) regardless of outside
temperature.
The engine block and oil pan
heaters are designed to warm the
block and oil pan areas that will let
the engine run faster. To use the
heaters:
1. On single cab vehicles, tilt the cab. See Cab Tilting 0233.
2. Unwrap the electrical cord and remove the protective cap.

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
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