warning light CHEVROLET LOW CAB FORWARD 2020 Owner's 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
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
Instruments and Controls 79
Hour Meter
HOUR METER
This message and light indicate how
many hours the engine has been
run. The figure(s) on the left side of
the decimal point indicate hours
while the figure on the right side
indicates 1/10 of an hour.
Warning Buzzers
A warning buzzer may not sound if
there is a problem with the buzzer
system. If this occurs, the system
needs to be inspected. See your
dealer.
A warning buzzer sounds under the
following conditions:
.Driver seat belt not buckled —
continuous beep. See Seat Belt
Reminders 060.
. Brake booster —continuous
beep. See Brake System
Warning Light (Parking Brake
Light) 062.
. Engine overheat —
continuous beep .
Parking brake on —
continuous beep
. Low engine coolant —beep
. Engine alarm and automatic
shutdown —beep
. Diesel particulate filter (DPF)
switch regeneration —three
short beeps or three long beeps
. Selective catalytic reduction
(SCR) system —one short
beep, three short beeps, nine
quick beeps, continuous beep
See Diesel Exhaust Fluid 0180 and
Engine Alarm and Automatic
Shutdown 0164.

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
80 Lighting
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . . 80
Headlamp High/Low-BeamChanger . . . . . . . . . . . . . . . . . . . . . . 81
Flash-to-Pass . . . . . . . . . . . . . . . . . . 81
Hazard Warning Flashers . . . . . . 82
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . . 82
Cornering Lamps . . . . . . . . . . . . . . 83
Interior Lighting
Instrument Panel Illumination Control . . . . . . . . . . . . . . . . . . . . . . . 83
Cargo Lamp . . . . . . . . . . . . . . . . . . . 84
Dome Lamps . . . . . . . . . . . . . . . . . . 84
Exterior Lighting
Exterior Lamp Controls
Turning the light control switch to
the following positions will cause the
relevant lights to illuminate.
The light control switch can be used
when the engine control switch is
placed in the LOCK or ACC
position. Do not operate the
combination lights for an extended
time period with the engine off.
Otherwise, the battery may go dead,
making it impossible to restart the
engine.
9: Turns off all exterior lights.
;:Turns on the parking lights
including all exterior lights, except
the headlights.
2: Turns on the headlights
together with the parking lights,
sidemarker lights, roofmarker lights,
taillights, license plate light, and
instrument panel lights.
When you start the engine in
daytime, with the lighting switch off,
and release the parking brake, the
daytime running lights will come on.
See Daytime Running Lamps (DRL)
Indicator Light 069 and
Turn and Lane-Change Signals
0 82.

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
82 Lighting
Hazard Warning Flashers
Use the hazard warning light flasher
to warn other drivers any time your
vehicle becomes a traffic hazard,
day or night. With the engine control
switch in any position or the key
removed, when this switch is
pressed, all of the turn signal lights
and the turn signal indicator lights
flash to signal an emergency. To
turn off the hazard lights, press the
switch again.Do not leave the hazard warning
light flasher operating for an
extended time period with the
engine off. Otherwise, the battery
may go dead, making it impossible
to restart the engine.
Both indicator lights flash when the
hazard warning flasher switch is
operated irrespective of the position
of the engine control switch.
The individual turn signals do not
work when the hazard flasher is
turned on.
Turn and Lane-Change
Signals
When turning left or right, move the
lever up or down to flash the turn
signal light.
When the turn is completed, the
signal will cancel and the lever will
return to horizontal.
If the steering wheel is only turned a
small amount, turn off the signal
manually. Lightly press and hold the
lever up or down when overtaking or
changing lanes. The turn signal light
continues flashing as long as 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
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.

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 131
Pulling Away After Stopping
and Parking
Before pulling away, check that
there are no children or obstructions
around the vehicle and confirm that
it is safe to pull away.
If you cannot see the area behind
your vehicle well enough to confirm
it is safe to back up, get out of the
vehicle and check behind it.
Make it a habit to look around and
confirm that it is safe to pull away
after a temporary stop (at traffic
lights, for example).
If the Windshield Fogs Up
Use the heater to blow hot air on the
windshield or dehumidify the cabin
using the air conditioner and place
the outlet selector knob in the
5or
4position.
Place the air selector lever in the
outside air position.
Nighttime Visibility
If there is an old film on the
windshield, the lights of oncoming
traffic will be reflected in many directions, making it hard for you to
see ahead. Use glass cleaner to
clean the glass and the wiper
blades.
Worn wiper blades cannot wipe the
windshield clean and thus cannot
maintain visibility. When the wiper
blades become worn, replace them
with new ones.
Do Not Attach Accessories to
the Windshield or Windows
{Warning
Do not attach ornaments, films or
other accessories to the
windshield or windows. They
would impair visibility. Also, any
plastic suction cups used to
attach accessories could cause a
fire or a crash by acting as
lenses.
You and others could be seriously
injured.
Never Stop the Engine While
Driving
{Warning
Do not move the engine control
switch away from the "ON"
position while the vehicle is being
driven.
If the engine stops while the
vehicle is moving, the brake
booster does not work, and the
brakes would not work properly.
The engine could also be
damaged.
Stopping the engine while driving
would be extremely dangerous
because the power steering
would stop working, making the
steering wheel extremely hard
to turn.
Stopping the engine while driving
would be extremely dangerous
because the warning lights,
(Continued)

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 135
time, the amount of force applied to
the brake pedal and the speed of
the vehicle.
When driving, bear the stopping
distance in mind. Maintain a speed
and headway distance that allow
you to stop safely even if a hazard
occurs.
Overriding Accelerator with
Brakes
In the unlikely event the accelerator
pedal becomes stuck, apply the
brakes firmly and steadily to reduce
engine power and bring your vehicle
to a safe stop. Turn the engine off,
move the selector lever to the“P”
(Park) position, and apply the
parking brake. In a safe location,
inspect the accelerator pedal for any
interference and remove the item
causing the interference, if any is
found. If none is found and the
condition persists, have your vehicle
towed to the nearest authorized
dealer.
Braking Techniques
For the most effective braking and
for maximum life from brake system
components, follow these
suggestions when possible:
. Apply the brakes gradually as
road and load conditions permit.
Reduce pedal pressure as
speed drops so that a very light
pressure is used at the end of
the stop.
. Do not pump the brake pedal as
this will only deplete the vacuum
reserve or the hydraulic brake
booster (HBB) accumulator
reserve.
. To get maximum braking while
maintaining vehicle control, use
a "squeeze" braking technique.
Do this by pushing on the brake
pedal with steadily increasing
pressure. If possible, steer
around obstacles when there is
not enough room to stop. Brake System Warning LightCaution
If brake low vacuum warning light
(4500HD, 4500XD models), brake
booster warning light (5500HD,
5500XD models), or brake system
warning light comes on during
operation, have brake system
checked immediately.
Refer to Warning Lights, Gauges,
and Indicators 056.
When the Brakes Do Not Work
{Warning
It is very dangerous to suddenly
pull the parking brake lever all the
way while moving at high speed.
Reduce speed first by shifting
down and then gradually pull the
parking brake lever.
You and others could be seriously
injured.

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.