Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
24 In Brief
Performance and
Maintenance
Driving for Better Fuel
Economy
Economical Driving
How you drive, where you drive and
when you drive all affect fuel
economy.
For diesel vehicles, driving too fast,
driving so slowly that the engine
knocks, driving with the exhaust
brake switched on all the time, and
frequently using the exhaust brake
to adjust your speed can lead to
poor fuel economy.
Drive at a constant speed as much
as possible. When accelerating,
increase your speed gently and
slowly, and up-shift early.
Maintain a constant cruising speed,
as traffic allows, and avoid sudden
stops.Frequent short trips, excessive
idling and use of the air conditioner
in cool weather when "Vent" would
provide adequate comfort, can all
lead to decreased fuel economy.
Warming up the engine for longer
than necessary, driving with the
vehicle overloaded and revving the
engine are a waste of fuel.
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.
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.
Diesel Exhaust Fluid
Diesel Exhaust Fluid (DEF) is used
with diesel engines to reduce the
amount of regulated emissionsproduced. The DEF system must be
maintained for the vehicle to run
properly.
DEF is not a fuel additive. For
refilling instructions, see
Diesel
Exhaust Fluid 0189. DEF should
not be mixed with or added to diesel
fuel. DEF freezes when exposed to
temperature below −11 °C (12 ° F).
Locating Diesel Exhaust Fluid
DEF can be purchased at a dealer.
It can also be purchased at
authorized vehicle and truck
dealerships. Additionally, some
diesel truck fueling stations or
retailers may have DEF for
purchase. See Recommended
Fluids and Lubricants 0349.
When the remaining level of DEF
becomes excessively low the DEF
gauge will change color from green
to amber. In addition, warning and
indicator lights will come on and
engine power will be reduced so the
vehicle speed will not exceed
89 km/h (55 MPH). See Diesel
Exhaust Fluid 0189.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Instruments and Controls 81
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) 082.
See Malfunction Indicator Lamp
(Check Engine Light) 073 and
Diesel Exhaust Fluid (DEF) Warning
Light 080.
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 093.
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 092.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
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 Coolant0253 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 0173 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
0 231.
If you continue driving with the
message displayed, the fuel
injection system may fail. See Water
in Fuel 0231.
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 0253.
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 0227,
Fuel Gauge 071, and Running Out
of Fuel 0233.
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
0 180.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Instruments and Controls 89
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 0189.
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
0 189.
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
90 Instruments and Controls
MAINTENANCE ON or
MAINTENANCE OFF
This indicator displays and hides
maintenance items. When
MAINTENANCE ON is displayed,
maintenance items will be
displayed. When MAINTENANCE
OFF is displayed, maintenance
items will not be displayed.
When MAINTENANCE OFF is
displayed, there will be no display of
maintenance items such as rotation
intervals or replacement intervals
even when such intervals arrive.
ENG OIL & FILTER
When this message and light
display green, it shows the distance
remaining until the next engine oil
and filter change. When this
message displays amber, the next
change of engine oil and filter is
near or has been reached.
T/M & DIFF OIL
When this message and light
display green, it shows the distance
remaining until the next
transmission oil and differential oilchange. When this message
displays amber, the next change of
transmission oil and differential oil is
near or has been reached.
FUEL FILTER
When this message and light
display green, it shows the distance
remaining until the next fuel filter
change. When this message
displays amber, the next change of
fuel filter is near or has been
reached.
STEERING OIL
When this message and light
display green, it shows the distance
remaining until the next power
steering fluid change. When this
message displays amber, the next
change of power steering fluid is
near or has been reached.
TIRE ROTATION
When this message and light show
green with OFF, it means the
vehicle has been shipped from the
factory with no tire rotation interval
set. When this message displays
green it has the distance until thenext tire rotation displayed. When
this message displays amber the
next tire rotation is near or has
already been reached.
STARTER
When this message and light is
green, it displays the number of
engine starts remaining until a
starter motor is replaced. When this
message and light is amber, it
displays when the time for a starter
motor replacement is near or has
already been reached.
For the starter indicator light, the
displayed color will change from
green to amber when the display
reaches zero and the screen is
selected.
For resetting or setting maintenance
data intervals, see
Driver
Information Center (DIC) 082.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
92 Lighting
Lighting
Exterior Lighting
Exterior Lamp Controls . . . . . . . . 92
Headlamp High/Low-BeamChanger . . . . . . . . . . . . . . . . . . . . . . 93
Flash-to-Pass . . . . . . . . . . . . . . . . . . 93
Hazard Warning Flashers . . . . . . 94
Turn and Lane-Change Signals . . . . . . . . . . . . . . . . . . . . . . . 94
Cornering Lamps . . . . . . . . . . . . . . 95
Interior Lighting
Instrument Panel Illumination Control . . . . . . . . . . . . . . . . . . . . . . . 95
Cargo Lamp . . . . . . . . . . . . . . . . . . . 96
Dome Lamps . . . . . . . . . . . . . . . . . . 96
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 081 and Turn and
Lane-Change Signals 094.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Lighting 93
Headlamp High/
Low-Beam Changer
With the headlights on, move the
lever forward and backward to
switch between the high beam and
low beam.
Moving the lever forward selects
high beam; moving the lever
backward selects low beam.
While the headlights are on high
beam, the headlights high beam
indicator light on the instrument
panel remains on.
This indicator light comes on when
high beam is selected or the
headlights are cycled between high
and low beams.
Use low beam whenever there are
vehicles ahead in the same lane or
oncoming vehicles in the
opposite lane.
SeeBulb Replacement 0277.
Flash-to-Pass
By lightly pulling the light control
switch lever and releasing it, the
high beam comes on and off. At the
same time, the headlights high
beam indicator light on the
instrument panel comes on and off.
Use this function as a signal for
flash-to-pass a vehicle or other
purposes.
Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
94 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 theengine 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