2020 CHEVROLET LOW CAB FORWARD check engine 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
Instruments and Controls 69
Reduced Engine Power
Light
This light comes on briefly when the
engine control switch is turned to
the ON position, and then should go
out after the engine is started.
If this light comes on while the
engine is running, it indicates power
is being reduced due to one or more
of the following conditions:
.Malfunction of the engine or
exhaust electronic control
system.
. DEF level is too low or empty.
If this light comes on with the
malfunction indicator lamp, see your
dealer immediately. If this light comes on with the Refill
Diesel Exhaust Fluid (DEF) warning
light and the DEF warning light, refill
DEF as soon as possible.
See
“Refill Diesel Exhaust Fluid
(DEF) Warning Light” underDriver
Information Center (DIC) 070. See
Malfunction Indicator Lamp (Check
Engine Light) 061 and
Diesel Exhaust Fluid (DEF) Warning
Light 068.
High-Beam On Light
This light comes on when the
high-beam headlamps are in use or
the headlamps are cycled between
high and low beams (passing
signal).
See Headlamp High/Low-Beam
Changer 081.
Daytime Running Lamps
(DRL) Indicator Light
This light comes on when the DRL
are on. If the vehicle is started
during the daytime with the lighting
switch off and the parking brake
released, the low beam headlamps
will come on at a reduced
brightness. The light will go out
when the lighting switch is
turned on.
See Exterior Lamp Controls 080.

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
72 Instruments and Controls
Red means the battery voltage is
too low or too high. If the voltmeter
sign appears in red, have the
vehicle checked and serviced at
your dealer. During or immediately
after the engine is started, a red
abnormal L voltage may display on
the DIC. If the warning disappears
after the engine has started, there is
no problem with the battery voltage.
Calendar and Clock
{Warning
The calendar and clock can be
set only while the vehicle is
stationary. When setting the
calendar or clock, park your
vehicle in a safe place where
stopping or parking is permitted
and that is well clear of traffic.
Press the DIC selector once or
more to select the calendar. Press
and hold the DIC selector to enter
the clock setting screen. The year
segment will flash. Turn the DIC
selector clockwise or
counterclockwise to increase or decrease the year. While in the year
setting screen, press the DIC
selector once to switch to the month
setting screen. The month segment
will flash. Use the same method to
set the month. While in the month
setting screen, press the DIC
selector again to switch to the day
setting mode. Adjust the day using
the selector.
Press and hold the DIC selector to
complete the calendar setting.
When complete, the normal
calendar display will resume. Use
this same method to set the hour
and minute when in the clock setting
screen.
Dimmer
The brightness of the DIC can be
adjusted while the light control
switch is off. Select this screen and
turn the DIC selector clockwise or
counterclockwise to brighten or dim
the illumination. The brightness is
linked to the adjustment of the
instrument panel light level control
while the light control switch is on.
See
Instrument Panel Illumination
Control 083.
Warning Lights and Messages
.
Engine Overheat Warning Light
. Low Coolant Warning Light
. Water Separator Warning Light
. Air Cleaner Light
. Low Fuel Warning Light
. Regeneration Warning Lights
. Exhaust System Warning Light
. Refill DEF Warning Light
. DIC Errors
. Maintenance Data
. Hour Meter
See Vehicle Messages 074.
Maintenance Data Functions
Display/Not Display the
Maintenance Data Function
Maintenance Light: On the DIC, go
to the Maintenance Indicator Light.
Switch the display by pressing and
holding the DIC selector for more
than two seconds. Turn the DIC
selector clockwise or
counterclockwise to switch the

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
Instruments and Controls 75
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 Coolant0243 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 0164 and
Engine Shutdown Warning Light
0 68.
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
0 221.
If you continue driving with the
message displayed, the fuel
injection system may fail. See Water
in Fuel 0221.
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 0243.
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 0218,
Fuel Gauge 059, and Running Out
of Fuel 0224.
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
0 171.

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
76 Instruments and Controls
If your vehicle is equipped with a
power take-off (PTO), monitor the
DIC for DPF related indicators. PTO
and other slow speed applications
may require more attention.
Selectable (Switch)
Regeneration Required
Warning Light
SEL REGEN. REQUIRED
Performing the“Selectable”
regeneration: After the Checking PM
Level Light is shown, this light
comes on in amber when
“Selectable” regeneration is
possible. When the DPF switch is
pressed with this light ON,
"Selectable" regeneration starts.
When the selectable regeneration or
switch regeneration is interrupted:
This light (amber) comes on when
the "Selectable" regeneration or
"Switch" regeneration is interrupted.
When this light comes on, perform
DPF regeneration promptly by
following the procedure for the
"Switch" regeneration. If you
continue to operate the vehicle
without performing DPF regeneration, the color of this light
changes to red from amber. When
this light comes on in red, perform
DPF regeneration immediately by
following the procedure for the
switch regeneration. 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 situation happens,
the vehicle must be serviced. See
Diesel Particulate Filter
0171.
If your vehicle is equipped with a
power take-off (PTO), monitor the
DIC for DPF related indicators. PTO
and other slow speed applications
may require more attention.
Regeneration in Progress
Light
REGEN. IN PROGRESS
When this light is ON, DPF
regeneration is in progress. When
the vehicle is stationary, the exhaust
sound changes as the engine speed
increases. Also, operating sounds of
the exhaust throttle may be heard. Keep people and flammable objects
away from the exhaust pipe,
because the exhaust temperature
becomes high during regeneration.
When regeneration is completed,
the light goes out automatically. See
Diesel Particulate Filter
0171.
During extended engine idling, this
light may appear on the DIC and the
DPF may be automatically
regenerated.
Checking PM Level Light
CHECKING PM LEVEL
In the case of performing the
"Selectable" regeneration, this light
comes on when the DPF switch is
kept held down. While this light is
ON, the system is checking whether
or not the "Selectable" regeneration
is possible. If the "Selectable"
regeneration is possible, the light
changes to the selectable (switch)
regeneration required warning light.
If the indication does not change to
the selectable (switch) regeneration
required warning light, the
"Selectable" regeneration is not
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
Instruments and Controls 77
Exhaust System Warning Light
EXH. SYSTEM
This light comes on when the SCR
system detects a malfunction or
incorrect DEF. SCR system will turn
on other indicator lights and reduce
engine power in progressive stages
to encourage you to have the
malfunction corrected. Continuing to
drive for too long after this light
turns on will eventually result in a
severe vehicle speed limitation.
If this light turns on, promptly have
the vehicle inspected and serviced
at your dealer. SeeDiesel Exhaust
Fluid 0180.
Refill Diesel Exhaust Fluid
(DEF) Warning Light
REFILL DEF
This message displays and a
warning light appears when the DEF
tank is almost empty. Add DEF as
soon as possible.
Engine power will be reduced and
vehicle speed will be limited when
this light is activated. Failure to
promptly refill the DEF tank will result in a severe vehicle speed
limitation. See
Diesel Exhaust Fluid
0 180.
When DIC ERROR is Displayed
ERROR
If the system has not yet been able
to access maintenance data,
ERROR is shown on the DIC.
If ERROR does not change
automatically to a distance or other
maintenance indication, have your
vehicle serviced at your dealer.
Maintenance Data Indicator
Lights
Maintenance data indicator lights
appear on the DIC when each
maintenance item is selected or
when the next change or service
interval of the item is near or has
been reached.
The distance or time shown is the
remaining or excess of them to /
from the change or service timing.
The positive distance or time shows
the remaining of that and the
negative distance or time shows the excess of that. For the items listed
below, the displayed color will
change from green to amber when
remaining distance is below
1 600 km (1,000 mi) and the screen
is selected.
These screens are also displayed
when the engine control switch
turns to the ON position after above
notification timing. The message
remains on the display until the DIC
selector is pressed once or the
vehicle is started.
The maintenance data function
indicates the distance remaining
before the next scheduled
maintenance. Scheduled
maintenance time is approaching
when the display turns from green
to amber. Have the vehicle checked
and serviced at your dealer as soon
as possible.
The vehicle needs to be maintained
more often if it is driven in severe
conditions.

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
Lighting 83
lever is held up or down. The lever
moves back to neutral as soon as it
is released.
A green light on the instrument
panel is designed to flash to tell you
that the front and rear turn signal
lights are working. If the light stays
on, but does not flash, check for a
burned-out turn signal bulb. If the
green light does not come on when
you move the lever, check the fuse
and indicator bulb.
Either of these indicator lights
flashes when the turn signal switch
is operated with the engine control
switch in the ON position.
Cornering Lamps
The cornering light illuminates the
area to which the vehicle is turning.
With the headlights or marker lights
on, the cornering lights come on in
coordination with the turn signal
lights.
SeeExterior Lamp Controls 080
and
Bulb Replacement 0267.
Interior Lighting
Instrument Panel
Illumination Control
The control will change the light
level of the instrument panel.

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
130 Driving and Operating
The careful attention you give your
vehicle, as far as maintenance is
concerned, will also help fuel
economy.
Protection of Engine against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.
Distracted Driving
Do Not Use a Mobile Phone
While Driving
{Warning
Drivers should never use mobile
telephones or car phones in any
mode other than Hands Free
while driving. Doing so is
dangerous. Using a mobile
telephone while driving could
result in a crash because you
would not be paying full attention
to your surroundings. If you are(Continued)
Warning (Continued)
driving and you wish to use a
mobile telephone, first stop the
vehicle in a safe place.
You and others could be seriously
injured.
Control of a Vehicle
Warnings for Driving
{Warning
Concentrate on driving safely,
obeying all legally designated
speed limits, road signs and
traffic signals.
If you notice any abnormal noise,
abnormal smell or abnormal
vibration from any part of the
vehicle, immediately stop the
vehicle in a safe place and
perform checks.
(Continued)
Warning (Continued)
If a warning light comes on or a
buzzer sounds while you are
driving, immediately stop the
vehicle in a safe place and
perform checks.
Slow down sufficiently when
approaching a curve. Applying the
brakes or sharply turning the
steering wheel while turning the
curve could cause the cargo to
shift, the tires to slip and the
vehicle to tip onto its side.
Avoid scraping the tire sidewalls
against curbstones or driving over
dips and protrusions in the road
surface. You could damage the
tires, resulting in a blowout or
flat tire.
You and others could be seriously
injured.