Page 88 of 358

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Instruments and Controls 87
Low Coolant Warning Light
LOW COOLANT
If this message and light come on,
the system is low on engine coolant
and the engine may overheat.
A warning tone also sounds. If this
light comes on while driving, stop
the vehicle immediately and check
the cooling system for leaks. See
Engine Coolant0231 and have the
vehicle serviced by your dealer. This
light will also activate the engine
alarm and automatic shutdown
system.
See Engine Alarm and Automatic
Shutdown 0155 andEngine
Shutdown Warning Light 080.
Water Separator (Fuel Filter)
Warning Light
WATER SEPARATOR
This message displays and a
warning light appears when the
level in the water separator on the
fuel line is beyond the specified
level. Drain water following the
instructions in the Water in Fuel section and make sure the warning
light goes out. See
Water in Fuel
0 209.
If you continue driving with the
message displayed, the fuel
injection system may fail. See Water
in Fuel 0209.
Air Cleaner Light
CHECK AIR FILTER
This message displays and a
warning light appears when the next
air cleaner element service interval
is near or has already been
reached.
Replace the air cleaner element.
See Engine Air Cleaner/Filter 0231.
Low Fuel Warning Light
LOW FUEL
This message displays and a
warning light appears when the fuel
level in the tank becomes too low
while the engine is running. Add fuel
at the earliest possible time. If the
vehicle runs out of fuel, air bleeding
procedure must be performed. See
Fuel for Diesel Engines 0206,
Fuel Gauge 072, and Running Out
of Fuel 0212.
Regeneration Required
Warning Light
REGEN. REQUIRED
This light (amber) comes on when
Running regeneration or Switch
regeneration is required. When this
light comes on, perform DPF
regeneration soon. If the engine
continues to run without performing
DPF regeneration, this light will
change color from amber to red.
If this light turns red, perform DPF
regeneration immediately. If you do
not perform DPF regeneration, the
check engine malfunction indicator
light and reduced engine power
indicator light will come on,
imposing performance restriction on
the vehicle. If this happens, the
vehicle must be serviced at your
dealer. See Diesel Particulate Filter
0 161.
Page 116 of 358

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Climate Controls 115
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . 115
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . 118
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . 119
Service . . . . . . . . . . . . . . . . . . . . . . . 120
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.
Page 120 of 358
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Climate Controls 119
Air Flow Direction Control Lever
Use the tab to adjust the airflow
direction from the outlet. To close
the outlet, move the tab fully down.
Maintenance
Passenger Compartment
Air Filter
Removing the Inside Air Filter
1. Remove the 2 clips securingthe cover. Remove the clips in
the order of the inner clip (1)
followed by the outer clip (2).
2. Remove the cover by pushing it upwards.
3. Remove and clean the filter.Use a vacuum cleaner or the
like to clean dust and dirt from
its surface.
Avoid interference with electric
harnesses when removing the filter.
In order to avoid filter damage, hard
brushes should not be used for filter
cleaning.
Installing the Inside Air Filter
Install the filter in the reverse order
to removal.
Ensure that the filter is returned
securely to its original position.
Failure to observe this precaution
can lead to rattling during travel.
Page 121 of 358

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
120 Climate Controls
The vehicle must not be used with
the filter removed or incorrectly
installed. Failure to observe this
precaution can lead to air
conditioning system damage as a
result of dust, dirt and the like
entering the system.
Removing the Outside Air Filter
1. Remove the filter from underthe instrument panel on the
passenger side. While pressing
in the filter lock, on both sides,
pull out the filter.
2. Use a vacuum cleaner or the like to clean dust and dirt from
its surface. In order to avoid filter damage, hard
brushes should not be used for filter
cleaning.
Installing the Outside Air Filter
Install the filter in the reverse order
to removal.
Ensure that the filter is returned
securely to its original position.
Failure to observe this precaution
can lead to rattling during travel.
The vehicle must not be used with
the filter removed or incorrectly
installed. Failure to observe this
precaution can lead to air
conditioning system damage as a
result of dust, dirt, water, snow, and
the like entering the system.
Service
The air conditioning system will not
be able to cool the cab interior
effectively if the refrigerant level is
low. Accordingly, the refrigerant
level must be topped up whenever
necessary.
Please contact your dealer
whenever refrigerant must be
added. Operation Tips
Operating the air conditioning while
the refrigerant level is too low leads
not only to poor cooling
performance but also to air
conditioning system damage.
This vehicle uses the new
refrigerant HFC134a (R134a) in the
air conditioning system. No other
type of refrigerant can be used. In
order to protect the environment,
care must be taken to ensure that
refrigerant gas is never released
into open air. When refrigerant must
be replaced, therefore, please
contact your dealer or other service
facility equipped with a gas recovery
installation system.
Page 140 of 358
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 139
SymptomCauseCorrective Action Reference
Engine does not
start Starter turns over No fuel
Make sure there are no
fuel leaks, and then
add fuel-
Air in the fuel system Bleed fuel system See
Running Out
of Fuel 0212
Fuel filter clogged
4-
Fuel is frozen Warm fuel pipe with hot
water or wait until it gets
warmer
-
Common rail system is
faulty
4-
Preheating system is
faulty
4-
Engine starts, but immediately stops Idling speed too low
4-
Fuel filter is clogged
4-
Air cleaner is clogged
4-
Common rail system is
faulty
4-
Fuel system is faulty
4-
Page 141 of 358
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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140 Driving and Operating
SymptomCauseCorrective Action Reference
Unsteady engine speed There is water or air in
the fuel system
Drain water from fuel
filter or bleed the systemSee
Running Out
of Fuel 0212 or
Water in Fuel
0 209
Fuel system is faulty
4-
White exhaust smoke Engine not sufficiently
warming up
Allow the engine to
warm up
-
Too much engine oil Correct the oil level See
Engine Oil
0 223
Engine Control system
faulty
4-
Fuel system faulty
4-
Exhaust injector
4-
Continuous idling for a
long period (more than
two hours) With the vehicle
stationary in a place
where it will not obstruct
traffic, hold down the
accelerator pedal and
check that white smoke
is not emitted
-
Page 142 of 358
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 141
SymptomCauseCorrective Action Reference
Black exhaust smoke Engine Control system
faulty
4-
The air cleaner clogged
4-
Fuel system faulty
4-
Exhaust system clogged
4-
Exhaust injector
4-
Diesel particulate filter
(DPF) faulty
4-
Engine is overheating No engine coolant Add engine coolant
See
Engine
Coolant 0231
Front of radiator is
clogged with dirt Wash clean with tap
waterSee
Exterior Care
0 293
Radiator cap not
sufficiently tightened Make sure it is firmly
tightened or replace the
radiator cap
-
Fan belt loose Adjust the tension or
replace the beltSee
Engine Drive
Belt Routing 0341
Engine coolant dirty
4-
Fan clutch is faulty
4-
Radiator cap dirty or
faulty Clean or replace -
Page 143 of 358
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
142 Driving and Operating
SymptomCauseCorrective Action Reference
Oil pressure is low Improper engine oil
viscosity
Change to an oil with
proper viscositySee
Engine Oil
0 223
Engine oil level too low Add engine oil See
Engine Oil
0 223
Engine inner
components are faulty
4-
Meter, indicator/warning
lights or switches faulty
4-
Not enough engine power Parking brake not fully
released
Make sure it is fully
released
-
Brake dragging
4-
Air cleaner clogged
4-
Fuel filter clogged
4-
Engine control system
faulty
4-
Common rail system
faulty
4-
Engine faulty
4-
DPF clogged
4-