warning lights 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
196 Driving and Operating
When the exhaust system warning
light comes on, promptly have the
vehicle inspected and serviced at a
dealer.
When a malfunction is detected in
the SCR system, the warning and
the indicator lights shown in the
table come on. SeeVehicle
Messages 074, Malfunction
Indicator Lamp (Check Engine
Light) 061, and Diesel Exhaust
Fluid (DEF) Warning Light 068.
When the Diesel Exhaust Fluid
(DEF) Tank is Empty
If the DEF tank is empty and
warning and indicator lights are on,
you must follow below procedure to
cancel the vehicle restriction: 1. Turn the engine control switch to the LOCK or ACC position,
and add DEF.
2. After adding DEF, turn the engine control switch to ON
position.
3. Wait until buzzer stops, warnings and indicators are
turned off. 4. If the buzzer does not stop,
return the engine control switch
back to the LOCK position and
add more DEF, and then start
over from step 2 above.
5. Restart the engine.
It may take a while until the warning
lights and indicators turn off and the
buzzer stops after turning the
engine control switch to the ON
position.
It is desirable to fill up the tank with
DEF to avoid DEF remaining level
warning indication from reappearing.
When the outside temperature is
low, refer to Adding DEF in Cold
Weather. See Driver Information
Center (DIC) 070, Brake System
Warning Light (Parking Brake Light)
0 62, Warning Buzzers 079, and
Winter Driving 0142.Automatic
Transmission
On an automatic transmission
vehicle, the driver does not use a
clutch pedal when pulling away,
changing gears, or stopping. Only
the selector lever, accelerator pedal,
and brake pedal are used.
Practice learning the characteristics
of the automatic transmission
vehicle and how to correctly operate
it. When the vehicle is stationary,
remember to keep the brake pedal
firmly pressed, and if necessary,
move the selector lever in the P or
N position and apply the parking
brake.
Creep : With the engine running
and a gear position other than P or
N selected with the selector lever,
power reaches the wheels even
when the accelerator pedal is not
pressed, causing the vehicle to tend
to move.

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
Vehicle Care 269
Bulb Wattage
PositionLights Bulb Wattage (12V)Qty.
Front Headlight Highbeam/Lowbeam 60/55W2
Front Turn Signal Lamp 27W (Amber)2
Parking Lamp 5W2
Cornering Lamp 27W2
Side Turn Signal Lamp 5W (Amber)2
Sidemarker Lamp 5W (Amber)2
Rear Taillamp and Stoplamp 8/27W2
Turn Signal Lamp 27W2
Back-Up Lamp 27W2
License Plate Lamp 7.5W1
Roof Roofmarker Lamp (Identification/Clearance Lamp) 5W
5
Interior Dome Light 10W1
Speedometer and Gauge Lights 3.4W5
Warning/Indicator Lights LED20
Contact your dealer when replacing
lights that are not listed here.

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
Service and Maintenance 331
Recommended Daily
(Pre-operation) Inspections
These checks are in addition to, not
instead of, any legally required daily
inspections. See related topics
under "Maintenance Schedule",
especially if problems are found.
For safe and comfortable driving,
keep record of the distances driven
and the condition of the vehicle
during operation. Perform
inspections at appropriate intervals,
and perform maintenance in
accordance with the findings of the
inspections. If an inspection reveals
an abnormality or there was an
abnormality the previous time the
vehicle was driven, have the vehicle
repaired by the nearest dealer
before it is driven again.1. Components that showed abnormalities during the
previous operation
.Check components that
showed abnormalities
during the previous
operation 2. Checks performed at the
engine
.Fan belt looseness and
damage
. Engine oil level
. Engine coolant level
. Power steering fluid level
3. Checks performed from the driver's seat
.Brake fluid level
. Brake pedal free play
. Operation of meters,
gauges and warning/
indicator lights
. Engine startability,
abnormal noise and color of
exhaust gases
. Parking brake lever stroke
. Windshield washer fluid
spray condition and
windshield wiper
effectiveness
. Windshield washer fluid
level .
Steering wheel position and
free play
. Operation of horn and turn
signal lights
. Door lock operation
4. Checks performed during a walk around the vehicle
.Illumination, flashing,
contamination, damage and
obstruction of lights
. Contamination, damage ad
obstruction of windows,
mirrors and reflectors
. Leaf spring damage
. Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Water separator
5. Checking wheels and tires .Air pressure
. Cracks and other damage
. Abnormal wear
. Tread depth

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
332 Service and Maintenance
.Mounting condition of all
wheel nuts
6. Checks performed after the engine startup
.Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Inspect the exhaust system,
checking that the tailpipe is
clear
7. Checks performed while driving the vehicle
.Brake effectiveness
. Engine abnormal noises
Keep the Floor Around the Driver
Seat Clean and Tidy
{Warning
It is extremely dangerous to have
empty cans, empty bottles,
or other items rolling around on
the floor because they could get
trapped under the brake pedal
and prevent brake application. (Continued)
Warning (Continued)
For proper pedal operation, it is
also essential to lay floor mats
properly. Incorrectly installed floor
mats would hinder free movement
of the pedals.
Do not use the dashboard pocket
or the top of the dashboard as a
place to put items that could roll,
which could interfere with your
driving. You and others could be
seriously injured.
Choose Your Footwear Suitable
for Driving
{Warning
Choose footwear that ensures
proper operation of pedals when
driving the vehicle. Use of
footwear unsuitable for driving
may cause an accident. The
driver could be seriously injured
when not wearing the proper
footwear.
Electrical System
Following the after-delivery service,
it is the owner's responsibility to
check all wiring periodically for
cracked, chafed or oil-soaked
insulation and maintain it in a clean
and tight condition to ensure
satisfactory operation of the
electrical system.
Headlights and Turn Signal
Lights
Turn the engine control switch to the
"ON" position, and then check the
way in which the headlights, turn
signal lights, and other exterior
lights come on and flash. In
addition, press the brake pedal to
confirm whether the stop lights
come on, and shift the transmission
to "R" position to confirm whether
the back up lights come on. Also
examine the lights for discoloration,
damage, and looseness.

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
Service and Maintenance 337
one side, unusual sounds when
braking, increased brake pedal
travel or harder pedal. The front and
rear brakes are attached to an auto
adjuster mechanism. If there are no
defects, as the pedal travel is
properly maintained, adjustments
are not necessary. Check regularly
that the brake fluid reservoir
(left-hand side of the instrument
panel) or HBB reservoir (5500HD,
5500XD models: left side behind the
cab) is properly filled and check for
fluid leaks. Any of these conditions
could indicate the need for brake
system inspection and/or service.
G: Exhaust System :Be alert for
any changes in the sound of the
exhaust system or any smell of
fumes. These are signs the system
may be leaking. Have it checked
and/or repaired at once. (Refer to
"Engine Exhaust Emissions Caution
(Carbon Monoxide)" under Engine
Exhaust 0168).
H: Windshield Wipers and
Washers : Check operation and
condition of the wiper blades. Check
the flow of the washer spray. I: Defroster :
Turn the outlet
selector knob to "Defroster" and the
fan speed control knob to the fully
clockwise position. Then check the
airflow from the ducts at the inside
base of the windshield.
J: Rearview Mirrors and Sun
Visors : Check that friction joints
hold mirrors and sun visors in place.
K: Horn : Sound the horn, now and
then, to be sure it works.
L: Lap-Shoulder Belts : Check the
seat belt system (including webbing,
buckles, latch plates and anchors)
for proper operation, and for
damage.
M: Seat Adjusters : When
adjusting the driver's manual seat,
be sure the seat adjusters latch by
pushing the seat forward and
backward. Do not attempt to adjust
the seat when the vehicle is in
motion.
N: Lamps : Check panel lighting,
warning lamps, indicator lamps and
interior lamps. On the outside,
check: license plate lamps, side
marker lamps, reflectors on outside mirrors, headlamps, parking lamps,
identification and clearance lamps,
taillights, brake lamps, turn signals,
cornering lamps, backup lamps and
hazard warning flashers. Have
headlamp aim checked immediately
if beams seem improperly aimed.
O: Glass, Mirrors, Lights and/or
Reflectors Condition :
Look for
broken, scratched, dirty or damaged
glass, mirrors, lamps or reflectors
that could reduce the view or
visibility, or cause injury. Replace,
clean or repair promptly.
P: Door Latches : Check that doors
close, latch and lock tightly. Check
for broken, damaged or missing
parts that might prevent tight
latching.
Q :Tilt Cab (Driving Position) : Be
sure the tilt lever is down and
locked.
R: Fluid Leaks : Check for fuel,
water, oil or other fluid leaks by
looking at the surface beneath the
vehicle after it has been parked for

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
368 Index
Fluid (cont'd)Power Steering . . . . . . . . . . . . . . . 252
Washer . . . . . . . . . . . . . . . . . . . . . . . 252
Frequency Statement
Radio . . . . . . . . . . . . . . . . . . . . . . . . . 362
Front Seat Position Seats Adjustment . . . . . . . . . . . . . . . . . . . . . 26
Fuel Biodiesel . . . . . . . . . . . . . . . . . . . . . 219
Cold Weather Operation . . . . . . 221
Diesel Engines . . . . . . . . . . . . . . . 218
Economy, Driving for Better . . . 129
Filling the Tank . . . . . . . . . . . . . . . 225
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Running out of Fuel . . . . . . . . . . . 224
Water in Fuel . . . . . . . . . . . . . . . . . 221
Fuel for Diesel Engines . . . . . . . . . 218
G
Gauges
Diesel Exhaust Fluid (DEF) . . . . . 60
Engine Coolant Temperature . . . 60
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Odometer . . . . . . . . . . . . . . . . . . . . . . . 58
Speedometer . . . . . . . . . . . . . . . . . . . 58
Tachometer . . . . . . . . . . . . . . . . . . . . . 59
Trip Odometer . . . . . . . . . . . . . . . . . . 58 Gauges (cont'd)
Warning Lights and
Indicators . . . . . . . . . . . . . . . . . . . . . 56
General Information
Vehicle Care . . . . . . . . . . . . . . . . . . 230
Getting In and Out of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 17
Glove Box . . . . . . . . . . . . . . . . . . . . . . . 43
GM Mobility Reimbursement Program . . . . . . . . . . . . . . . . . . . . . . . 358
H
Hazard Warning Flashers . . . . . . . . 82
HeadlampsAiming . . . . . . . . . . . . . . . . . . . . . . . . 267
Bulb Replacement . . . . . . . 267, 270
Daytime Running Lamps(DRL) Indicator Light . . . . . . . . . . 69
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 81
High-Beam On Light . . . . . . . . . . . . 69
High/Low Beam Changer . . . . . . . 81
Heated Mirrors . . . . . . . . . . . . . . . . . . . 22
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 163
Heating . . . . . . . . . . . . . . . . . . . . . . . . . 121
High Idle System . . . . . . . . . . . . . . . 165
High-Beam On Light . . . . . . . . . . . . . 69
Hill and Mountain Roads . . . . . . . . 141 Hooks
Shopping Bag . . . . . . . . . . . . . . . . . . 45
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
I
Idle Shutdown . . . . . . . . . . . . . . . . . . 164
Idle Shutdown Light . . . . . . . . . . . . . 68
Ignition Positions . . . . . . . . . . . . . . . 157
Information Publication Ordering . . . . . . . . . . 362
Information on Loading the
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 46
Instrument Cluster . . . . . . . . . . . . . . . 57
Instrument Panel Storage Area . . . . . . . . . . . . . . . . . . . 43
Instrument Panel
Overview . . . . . . . . . . . . . . . . . 8, 10, 11
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . 301
K
Keyless EntryRemote (RKE) System . . . . . . . . . 14
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

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
Index 369
L
LampsCargo . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Cornering . . . . . . . . . . . . . . . . . . . . . . . 83
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Exterior Controls . . . . . . . . . . . . . . . . 80
Interior . . . . . . . . . . . . . . . . . . . . . . . . 277
License Plate . . . . . . . . . . . . . . . . . 276
Malfunction Indicator (CheckEngine) . . . . . . . . . . . . . . . . . . . . . . . 61
Roofmarker . . . . . . . . . . . . . . . . . . . 274
Sidemarker . . . . . . . . . . . . . . . . . . . 274
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 36
Lighting Illumination Control . . . . . . . . . . . . . 83
Lights Antilock Brake System(ABS) Warning . . . . . . . . . . . . . . . . 64
Automatic Transmission
Fluid Temperature . . . . . . . . . . . . . 66
Battery Warning . . . . . . . . . . . . . . . . 61
Brake System Warning . . . . . . . . . 62
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . 61
Cruise Control . . . . . . . . . . . . . . . . . . 70
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 69
Diesel Exhaust Fluid (DEF) . . . . . 68 Lights (cont'd)
Engine Oil Level Indicator . . . . . . 67
Engine Oil Pressure . . . . . . . . . . . . 67
Engine Shutdown Warning . . . . . 68
Exhaust Brake . . . . . . . . . . . . . . . . . . 65
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 81
High-Beam On . . . . . . . . . . . . . . . . . . 69
High/Low Beam Changer . . . . . . . 81
Idle Shutdown . . . . . . . . . . . . . . . . . . 68
Overdrive Off . . . . . . . . . . . . . . . . . . . 66
Reduced Engine Power . . . . . . . . 69
Seat Belt Reminders . . . . . . . . . . . . 60
Service Transmission
Warning . . . . . . . . . . . . . . . . . . . . . . . 65
Service Vehicle Soon . . . . . . . . . . . 62
Wait to Start . . . . . . . . . . . . . . . . . . . . 67
Loading the Vehicle . . . . . . . . . . . . . . 46
Locks Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power Door . . . . . . . . . . . . . . . . . . . . . 21
M
Maintenance and CareAdditional . . . . . . . . . . . . . . . . . . . . . 336
Maintenance Schedule . . . . . . . . . 317 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . 339
Malfunction Indicator Lamp . . . . . . 61 Messages
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . 74
Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Heated . . . . . . . . . . . . . . . . . . . . . . . . . 22
N
New Vehicle Break-In . . . . . . . . . . . 156
Noise Control System . . . . . . . . . . 262
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . . 58Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Oil
Engine . . . . . . . . . . . . . . . . . . . . . . . . 235
Pressure Light . . . . . . . . . . . . . . . . . . 67
Online Owner Center . . . . . . . . . . . 357
Operating Temperature . . . . . . . . . 162
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Overdrive Off . . . . . . . . . . . . . . . . . . . 206
Overdrive Off Light . . . . . . . . . . . . . . 66
Overheating, Engine . . . . . . . . . . . . 249
Overview Instrument Panel . . . . . . . . 8, 10, 11
Owner Checks and Services . . . . 330

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
372 Index
Ventilation, Air . . . . . . . . . . . . . . . . . . 124
Visors . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
W
Wait to Start Light . . . . . . . . . . . . . . . 67
WarningBrake System Light . . . . . . . . . . . . . 62
Caution and Danger . . . . . . . . . . . . . 3
Warning Buzzers . . . . . . . . . . . . . . . . 79
Warning Lights, Gauges, and Indicators . . . . . . . . . . . . . . . . . . . . . . 56
Warnings
Hazard Flashers . . . . . . . . . . . . . . . . 82
Washer Fluid . . . . . . . . . . . . . . . . . . . 252
Water in Fuel . . . . . . . . . . . . . . . . . . . 221
Wheels and Tires . . . . . . . . . . . . . . . 285
Windows Power . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Windshield Wiper/Washer . . . . . . . . . . . . . . . . . . 54
Winter
Driving . . . . . . . . . . . . . . . . . . . . . . . . 142
Winter Cover . . . . . . . . . . . . . . . . . . . 163
Wiper Blade Replacement . . . . . . 265