check engine 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
Seats and Restraints 39
2. Mix one part neutral detergentinto approximately twenty parts
warm water.
3. Wet a nail brush or another similar brush having soft
bristles (of nylon or the like) in
warm water, and use this to
clean away dirt.
4. Wipe the seat belt dry using a dry cloth, and then allow it to
dry naturally out of direct
sunlight.
5. Check to be sure the seat belt retracts and pulls out correctly. If the above-described upkeep
operations do not improve the
operation of the seat belt through
the retractor, there is a possibility
that the belt is making contact with
the door pillar trim. In this case,
arrange for inspection and
maintenance to be carried out by
your dealer.
If the belt is not winding and
unwinding correctly, or if inspection
reveals problems such as loose
mountings, metal parts deformation,
webbing damage, fraying or
discoloration, arrange for
replacement to be carried out by
your dealer.Child Restraints
Child Restraint Systems
{Warning
Children small enough for child
restraints (as indicated on the
label of such restraints), including
booster seats, should always be
transported in them. Children who
have outgrown child restraint
systems should wear seat belts.
The lap belt should be snug and
positioned low on the abdomen
so that it is below the top of the
hipbone. Otherwise, the belt could
intrude into the child's abdomen
during an accident and cause
personal injury. When a child has
grown enough so that the
shoulder belt can be worn, a
seating position with a shoulder
belt should be chosen whenever
possible.
(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
52 Instruments and Controls
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . . 53
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Windshield Wiper/Washer . . . . . . 54
Power Outlets . . . . . . . . . . . . . . . . . 55
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . 56
Instrument Cluster . . . . . . . . . . . . . 57
Speedometer . . . . . . . . . . . . . . . . . . 58
Odometer . . . . . . . . . . . . . . . . . . . . . . 58
Trip Odometer . . . . . . . . . . . . . . . . . 58
Tachometer . . . . . . . . . . . . . . . . . . . . 59
Fuel Gauge . . . . . . . . . . . . . . . . . . . . 59
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . . . 60
Diesel Exhaust Fluid (DEF) Gauge . . . . . . . . . . . . . . . . . . . . . . . . 60
Seat Belt Reminders . . . . . . . . . . . 60
Battery Warning Light . . . . . . . . . . 61
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . . 61
Service Vehicle Soon Light . . . . 62 Brake System Warning Light
(Parking Brake Light) . . . . . . . . . 62
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . 64
Exhaust Brake Light . . . . . . . . . . . 65
Service Transmission Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . 65
Automatic Transmission Fluid Temperature Warning Light . . . 66
Overdrive Off Light . . . . . . . . . . . . . 66
Wait-to-Start Light . . . . . . . . . . . . . 67
Engine Oil Pressure Light . . . . . . 67
Engine Oil Level Indicator Light . . . . . . . . . . . . . . . . . . . . . . . . . 67
Diesel Exhaust Fluid (DEF) Warning Light . . . . . . . . . . . . . . . . 68
Engine Shutdown Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . 68
Idle Shutdown Light . . . . . . . . . . . . 68
Reduced Engine Power Light . . . . . . . . . . . . . . . . . . . . . . . . . 69
High-Beam On Light . . . . . . . . . . . 69
Daytime Running Lamps (DRL) Indicator Light . . . . . . . . . . . . . . . . 69
Cruise Control Light . . . . . . . . . . . 70
Information Displays
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . 70
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . 74
Warning Buzzers . . . . . . . . . . . . . . 79

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 55
To spray washer fluid on the
windshield, push the button on the
end of the combination switch lever.
The spray will continue as long as
you hold in the button.
If windshield washer fluid does not
come out in sufficient quantity,
immediately release the switch.
Otherwise, the windshield surface
may sustain damage.
If windshield washer fluid does not
come out, release the windshield
washer switch immediately.
Otherwise the motor may seize up.
Do not hold the switch pressed for
more than 30 seconds. Otherwise,
the washer pump may sustain
damage.
Check the washer fluid level
regularly. Do it often when the
weather is bad.
SeeWasher Fluid 0252 for
information on filling the windshield
washer fluid resevoir.Power Outlets
You can plug in auxiliary electrical
equipment. Just flip the outlet cover
open from the left edge of the cover
and follow the proper installation
instructions that are included with
any electrical equipment you install.
These circuits are protected by a
fuse and have maximum current
loads. When using accessory power
outlets, total maximum electrical
load must not exceed 120W. Always
turn off any electrical equipment
when not in use.
Leaving electrical equipment on for
extended periods will drain your
battery.

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
56 Instruments and Controls
Warning Lights,
Gauges, and
Indicators
Warning lights and gauges can
signal that something is wrong
before it becomes serious enough
to cause an expensive repair or
replacement. Paying attention to the
warning lights and gauges could
prevent injury.Some warning lights come on briefly
when the engine is started to
indicate they are working. When
one of the warning lights comes on
and stays on while driving, or when
one of the gauges shows there may
be a problem, check the section that
explains what to do. Waiting to do
repairs can be costly and even
dangerous.
For safety reasons, do not place
packages, tools, or other items in
the driver
’s area that may restrict
access to the controls or sight of the
gauges.

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
58 Instruments and Controls
Speedometer
The speedometer shows the
vehicle's speed in either kilometers
per hour (km/h) or miles per
hour (mph).
Odometer
The odometer shows how far the
vehicle has been driven, in either
kilometers or miles.
Each time the reset knob is pressed
with the engine control switch in the
ON position, the odometer/trip meter
shows ODO, TRIP A, and TRIP B in
this sequence. With the key
removed, the odometer and trip
meter continue to indicate for about
five minutes.
Odometer Check Switch
Press the Odometer Check switch
to display the odometer and trip
meter mileage after the key is
turned off. The fuel gauge will also
operate when this switch is pressed.
The DIC and some lights will
illuminate on the instrument panel.
Trip Odometer
The trip odometer shows how far
the vehicle has been driven since
the trip odometer was last reset.
Press the trip odometer reset stem
next to the odometer to switch
between the odometer and trip
odometer.To reset the trip odometer to zero,
press and hold the trip odometer
reset stem while TRIP A or TRIP B
is displayed. The engine control
switch should be in the ON position.
When the battery is disconnected,
TRIP A and TRIP B will be reset to
zero. The per trip fuel economy is
also reset by the TRIP B reset. See
Driver Information Center (DIC)
0
70.
When you turn the engine control
switch to the ON position, the
odometer/trip odometer shows what
was displayed the last time the
engine control switch was turned to
LOCK or ACC.
To set the odometer to display each
time you turn the engine control
switch to the ON position, turn the
engine control switch to LOCK or
ACC while the odometer is
displayed. With the reset stem
pressed, turn the engine control
switch to the ON position and then
within three seconds, turn the
engine control switch back to 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
Instruments and Controls 59
LOCK or ACC position. Follow the
same procedure to cancel the
setting.
Tachometer
The tachometer displays the engine
speed in revolutions per
minute (rpm). The red zone
indicates a range of dangerous
engine speeds beyond permissable
levels. Do not drive your vehicle
with the needle in the red zone.
Caution
Exercise extreme care when
shifting down on a steep
downslope. The engine speed
may exceed the critical speed,
which can damage the vehicle.
Fuel Gauge
With the engine control switch in the
ON position, the fuel gauge
indicates about how much fuel is left
in the tank.To check the fuel level with the
engine control switch in the LOCK
position, press the Odometer Check
switch.
Fill the tank well before it
approaches empty. After filling up
the fuel tank, it takes awhile for the
fuel gauge needle to stabilize after
the engine control switch is turned
to the ON position. If the fuel tank is
filled while the engine is off, but the
engine control switch is in the ON
position, the fuel gauge needle
takes awhile to show the correct
reading.
See
“Low Fuel Warning Light” in
Driver Information Center (DIC) 070
and
Running Out of Fuel 0224.

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
60 Instruments and Controls
Engine Coolant
Temperature Gauge
With the engine control switch in the
ON position, this gauge indicates
the temperature of the engine
coolant.“C”means cold while “H”
means hot. During operation, the
needle should stay in the safety
zone. See Engine Overheating
0 249.
{Warning
If the engine coolant temperature
gauge shows an overheat
condition or you have any other
reason to suspect the engine may
be overheating, continued
operation of the engine, even for
a short time, may result in a fire
and the risk of personal injury and
severe vehicle damage. Take
immediate action as outlined in
Engine Overheating. See Engine
Overheating 0249.
Caution
If the needle goes up above the
upper limit and enters the H zone,
the engine is likely to overheat.
Immediately pull safely off the
road out of the way of traffic and
take the necessary actions to
deal with engine overheating.
If the needle nears the H zone but
(Continued)
Caution (Continued)
does not cross into it, this is not a
problem, but check the engine
coolant level in the reservoir. Add
engine coolant as necessary.
See “Engine Overheat Warning
Light” under Driver Information
Center (DIC) 070 and
Engine Coolant 0243.
Diesel Exhaust Fluid
(DEF) Gauge
The DEF gauge is part of the Driver
Information Center (DIC). See
Driver Information Center (DIC)
070.
Seat Belt Reminders
Seat Belt Warning Light
There is a driver seat belt reminder
light on the instrument cluster.

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 61
This warning light comes on and a
warning buzzer sounds when the
driver is not wearing the seat belt
while the engine control switch is in
the ON position.
When the vehicle speed exceeds
20 km/h (12 mph) with the seat belt
unbuckled, the warning light will
flash and the buzzer will continue to
sound. The warning light will go out
and the warning buzzer will stop
when the driver buckles the
seat belt.
Battery Warning Light
This light comes on briefly when the
ignition is turned on, but the engine
is not running, as a check to show
the light is working. It should go out
when the engine is started.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging
system (such as a loose or broken
fan belt). Pull off to a safe place well
clear of traffic and contact your
dealer. Driving while this light is on
could drain the battery.
Check and Corrective Action1. Check to see if the fan belt is broken or loose.
2. If the fan belt is loose, adjust the tension.
3. If the fan belt is broken or there is no abnormality in the fan
belt, see your dealer for
service.
See Battery - North America 0259,
Jump Starting - North America
0 301, and Engine Drive Belt
Routing 0355.Malfunction Indicator
Lamp (Check Engine
Light)
This light should come on to show
that it is working when the engine
control switch is turned to the ON
position, and then should go out
after the engine is started.
If this light stays on or comes on
while the engine is running, it
indicates a malfunction with the
engine electronic emission control
system. Avoid driving at high
speeds and have the vehicle
inspected by your dealer.
If this light comes on when the fuel
tank is empty, you do not need to
have your vehicle serviced. See
Running Out of Fuel 0224.

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
62 Instruments and Controls
If this light comes on intermittently
or continuously while driving,
service is required. Even if the
vehicle is drivable and does not
require towing, see your dealer as
soon as possible. Continued driving
without having the system serviced
could cause damage to the
emission control system. It could
also affect fuel economy and
drivability.
Service Vehicle Soon
Light
This light comes on briefly when the
engine control switch is in the ON
position, but the engine is not
running, as a check to show the
light is working. It should go out
when the engine is started.If the light stays on, or comes on
while driving, the vehicle control
system may be malfunctioning. Take
the vehicle to your dealer for service
as soon as possible.
Brake System Warning
Light (Parking Brake
Light)
This light should come on briefly
when the engine control switch is
turned to the ON position, and then
should go out after the engine is
started.
Brake System Warning Light
If the light remains on after engine
start up or comes on during
operation of the vehicle, it means
that there is something wrong with
part of the brake system.The brake system warning light
comes on while the engine is
running (after startup) in the
following situations:
.
Drop in the level of brake fluid
(due to brake lining wear or fluid
leakage).
. Abnormality in the charging
system (such as an alternator
malfunction or loose or split
fan belt).
. Abnormality in the anti-lock
brake system (ABS) and
Electronic Braking force
Distribution (EBD) functions.
(The ABS warning light and
brake system warning light will
illuminate at the same time.) See
Antilock Brake System (ABS)
Warning Light 064.
To serve as a reminder, the light
should stay on when the parking
brake is not fully released, and the
engine control switch is on. Have
the system repaired if the light does
not come on when it should. If this

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 63
warning light does not go away,
brake inspection and maintenance
should be performed.
Check and Corrective Action
1. Check to see that the parkingbrake has been fully released.
If it has, check the following:
2. Turn on the exhaust brake to help slow the vehicle.
3. Pull off the road and stop carefully. Remember that
stopping distances may be
longer, the pedal may be
harder to push, and the pedal
may go down farther than
normal.
4. Check the brake fluid reservoir on the left side of the
instrument panel. If low, add
fluid as needed.
5. If the brake fluid is not low: Try out the brakes by starting and
stopping on the shoulder of the
road, then either drive
cautiously at a safe speed to
the nearest dealer for repair,
if you judge driving to be safe; or have the vehicle towed to
the nearest dealer for repair.
Continued driving without the
necessary repairs could be
dangerous.
If this warning light stays on, see
your dealer.
The regular braking system is a split
system designed so that one part
will provide some braking if there is
a loss of hydraulic pressure in the
other part of the system.
{Warning
If this warning light comes on
while the engine is running,
immediately stop the vehicle at a
safe place well clear of traffic and
contact your dealer for inspection.
When the brake system warning
light is illuminated, brake
effectiveness may be decreased.
When this happens, strongly
press the brake pedal.
See Brakes 0253.
Parking Brake Light
This indicator light comes on when
the parking brake lever is pulled
with the engine control switch on.
This light also stays on when the
parking brake is not fully released
and the engine control switch is on.
If this warning light stays on, see
your dealer.
The illumination of the parking brake
light does not necessarily ensure
firm application of the parking brake.
The parking brake lever must be
sufficiently pulled up and locked.
Be careful not to drive the vehicle
with the parking brake lever still
pulled up.