2020 CHEVROLET LOW CAB FORWARD heating

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
Instruments and Controls 67
Wait-to-Start Light
This light comes on when the
engine control switch is turned to
the ON position and goes out when
preheating is complete.
SeeStarting and Stopping the
Vehicle 0159.
Engine Oil Pressure Light
This light should come on briefly
when the engine control switch is
turned to the ON position, and then
should go out after the engine is
started. This light comes on when the
engine oil pressure has fallen below
the normal level while the engine is
running or the oil pressure across
the oil filter rises above the normal
level while the engine is running.
If the warning light comes on while
driving, immediately pull off to a
safe place and stop the engine.
Check the oil level in the engine
crankcase. If the oil level is normal,
restrictions are in the oil filter or
within the lubricating system. Have
the vehicle inspected at your dealer.
Do not run the engine with this light
on. It could damage the engine.
When this light comes on while
driving, a warning tone also sounds.
The oil level varies while the engine
is running right after it has stopped
or if the vehicle is on uneven
ground. As a result, the red engine
oil pressure warning light may
light up.
When checking the oil level, press
the engine oil level check switch on
level ground while the engine is
cool. The red engine oil pressurewarning light in combination with the
green engine oil level indicator light
can indicate if the engine oil level is
OK or low.
While driving, this light will also
activate the engine alarm and
automatic shutdown system.
See
Engine Oil Level Indicator Light
0 67 and
Engine Oil 0235.
Engine Oil Level Indicator
Light
When the engine oil level check
switch is pushed with the engine
control switch in LOCK, the green
engine oil level indicator light will
come on if the engine oil level
is OK.

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
Climate Controls 121
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . 121
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 124
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . 125
Service . . . . . . . . . . . . . . . . . . . . . . . 126
Climate Control
Systems
The heating, cooling, and ventilation
for the vehicle can be controlled
with this system.
Climate Control System w/Air
Conditioning shown, Heater Only similar
1. Outlet Selector Knob
2. Air Selector Lever
3. Temperature Control Knob
4. Air Conditioning (A/C) Switch, if equipped
5. Fan Speed Control Knob Outlet Selector Knob :
The Air
Selector Knob regulates air flow
from the upper, floor and defroster
outlets.
H: Air flows through the upper
outlets.
): Air flows through the upper and
floor outlets.
6: Air is flows through the floor
outlets.
-: Air flows through the floor
outlets, with some air coming from
the door window and windshield
outlets.
1: Air flows through the door
window and windshield outlets.
Air Selector Lever : The intake of
outside air and the circulation of
inside air is controlled by sliding this
lever right or left.
P: Use this position to ventilate
the interior of the cab. This position
should be normally selected.

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
Climate Controls 123
Maximum Heating :Turn the outlet
selector knob to the
6position, set
the air selector lever to the
O
position, and turn the temperature
control knob fully towards the high
temperature direction.
Set the fan speed control knob to
the maximum speed position.
Bi-Level Heating : Set the outlet
selector knob to the
)position. Set
the air selector lever to the
P
position. Set the temperature control
knob to the middle position.
Adjust the fan speed control knob
as desired. The air from the floor
outlets is warmer than the air from
the upper outlets in this position.
However, when the temperature
control knob is moved to either the
full hot or the full cold position, the
air from the floor outlets and the air
from the upper outlets will be the
same temperature. This position can
give cool upper level air and warm
floor level air when the temperature
control is adjusted in between cold and hot. This is useful in cool
weather with bright sunlight
conditions.
Defogging and Defrosting the
Windshield
Defogging :
Set the outlet selector
knob to the
1position. Set the air
selector lever to the
Pposition.
Turn the temperature control knob
to a high-temperature position
according to your preference. For
defogging in the summer months,
set the temperature control knob to
any desired position.
Set the fan speed control knob to
any speed position, except the off
position. The A/C compressor
automatically operates when the
1
position is selected. Defogging is
performed very effectively with the
dehumidifying effect.
Defrosting : Set the outlet selector
knob to the
1position. Set the air
selector lever to the
Oposition. Turn the temperature control knob
fully towards the high-temperature
direction. Set the fan speed control
knob to the maximum speed
position.
After defrosting, be certain to return
the air selector lever to the
P
position. Failure to do so will cause
the windshield to fog up, impeding
forward visibility.
Cooling
Normal/Moderate Cooling :
This
setting is suitable for extended
periods of cooling or moderate
cooling. Press the A/C switch to the
on position.
Set the outlet selector knob to the
Hposition for normal cooling or set
it to the
)position for moderate
cooling. Adjust the temperature
control knob to the desired position.
Adjust the fan speed control knob
as desired

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
136 Driving and Operating
The exhaust brake should be turned
on as soon as service brake
malfunction is detected. This will
slow the engine speed. With the
engine speed under control and
providing the grade conditions
permit, the transmission can be
progressively downshifted using the
exhaust brake in each gear.
Eventually the exhaust brake should
slow the vehicle to a controllable
“crawl.”Gradually pull the parking
brake lever while firmly holding on
to the steering wheel. Stop the
vehicle on the side of the road. The
vehicle should not be driven further
until corrective measures are taken.
See Exhaust Brake 0213 and
Parking Brake 0211.
Riding the Brake
{Warning
"Riding the brake" by resting your
foot on the pedal, when you do
not intend to brake, can overheat
the brakes and wear out the (Continued)
Warning (Continued)
brake linings faster. This may also
damage the brakes and will waste
fuel. It can also result in reduced
braking performance.
You and others could be seriously
injured.
Applying the Parking Brake
Except in an emergency, do not
apply the parking brake until the
vehicle has come to a complete
stop. Applying the parking brake
before the vehicle has stopped can
cause a breakdown.
Refer toParking Brake 0211.
Parking Safely on a Slope
Avoid parking your vehicle on a
slope as much as possible and
choose a level and flat place. If you
must park your vehicle on a slope,
be sure to set the parking brake
fully. Make sure that the vehicle
does not move, and block the
wheels with chocks for added safety. Also, leave the vehicle in
gear to further ensure that it will not
move. Leave the steering wheel
turned such that the vehicle will be
stopped by an obstruction (for
example, the curb) in the unlikely
event that it moves.
Stopping and Parking with the
Engine Running
{Warning
When parking with the engine
running, first come to a complete
stop, then firmly apply the parking
brake, then move the selector
lever to the "P" (Park) position.
Unless you take these steps, any
unintended pressure on the
accelerator pedal could cause a
crash.
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)