bulb CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

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
64 Instruments and Controls
Brake Low Vacuum Warning
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. If the light does not come
on when the engine control switch is
turned to ON, it could indicate a
burned out bulb or a blown fuse.
Have the system repaired if the light
does not come on during this check.
The warning light and buzzer will
come on simultaneously when the
brake booster’s vacuum or pressure
becomes insufficient either during
driving or when the engine control
switch is in the ON position, or when
there is an abnormality in the
charging system, such as an
alternator malfunction or loosening
or splitting of the fan belt or whenever the hydraulic brake
booster (HBB) becomes faulty. The
warning buzzer will stop sounding
when the parking brake is engaged.
On 4500HD and 4500XD, the brake
low vacuum warning light and
warning buzzer should come on to
indicate low vacuum reserve for
brake power assist. At the same
time, the Back up Electric Vacuum
Pump operates.
(5500HD, 5500XD models) When
the HBB pressure is low, and/or the
HBB fluid (Dexron
–VI) level is low,
the light and warning buzzer should
come on. Do not use brake fluid in
the brake booster reservoir. Use
only Dexron –VI ATF.
If this happens while driving:
. Do not pump the brakes. The
system is designed to stop the
truck with reserve power assist if
the pedal is held down. This
reserve is greatly reduced each
time you apply and release the
brakes.
. Stopping distance may be
longer. .
You may have to push much
harder on the brake pedal.
. Have the vehicle repaired before
you continue driving.
The buzzer stops when the selector
lever is shifted to the P position.
{Warning
Do not drive while the buzzer
sounds as the brakes are not
operating to their full capacity.
You and others could be seriously
injured.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine control switch is turned to
the ON position, and then should go

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 81
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.
See
Bulb Replacement 0267.
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 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
Vehicle Care 229
Vehicle Care
General Information
General Information . . . . . . . . . . 230
California Proposition65 Warning . . . . . . . . . . . . . . . . . 230
California Perchlorate Materials Requirements . . . . . 230
Accessories and Modifications . . . . . . . . . . . . . . . . 230
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 231
Cab Tilting . . . . . . . . . . . . . . . . . . . . 233
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 234
Engine Cover . . . . . . . . . . . . . . . . . 235
Engine Oil . . . . . . . . . . . . . . . . . . . . 235
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 241
Engine Air Cleaner/Filter . . . . . . 243
Engine Coolant . . . . . . . . . . . . . . . 243
Engine Overheating . . . . . . . . . . 249
Power Steering Fluid . . . . . . . . . 252
Washer Fluid . . . . . . . . . . . . . . . . . 252
Brakes . . . . . . . . . . . . . . . . . . . . . . . 253
Brake Fluid . . . . . . . . . . . . . . . . . . . 258
Battery - North America . . . . . . 259 Fuel Filter . . . . . . . . . . . . . . . . . . . . 260
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 261
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 262
Noise Control System . . . . . . . . 262
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 264
Wiper Blade Replacement . . . . 265
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 267
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 267
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 270
Roofmarker Lamps . . . . . . . . . . . 274
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 274
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 276
License Plate Lamp . . . . . . . . . . 276
Interior Lamps . . . . . . . . . . . . . . . . 277
Electrical System
Electrical System Overload . . . 277
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 285
Tire Pressure . . . . . . . . . . . . . . . . . 297
Tire Rotation . . . . . . . . . . . . . . . . . 297
If a Tire Goes Flat . . . . . . . . . . . . 300
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 301
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 305
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 307
Interior Care . . . . . . . . . . . . . . . . . . 313

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 267
2. Continue pushing in the wiperrubber insert until the wiper
blade's hook engages with the
hole in it, and then confirm that
the rubber insert is securely
held in place.
3. Attach the wiper blade to the wiper arm.Headlamp Aiming
For vertical aiming, turn the two
screws indicated by arrows in the
diagram.
1. Remove the rubber beneath the headlight.
2. Two screws should be turned in the same direction at the
same time to adjust aiming.
3. When the headlamp aiming is out of position, contact your
dealer.
Bulb Replacement
Caution
Do not replace incandescent
bulbs with aftermarket LED
replacement bulbs. This can
cause damage to the vehicle
electrical system.
Bulbs
1. Check each bulb for blowout.
2. If a bulb has blown out, replaceit. Always place the engine
control switch in the “LOCK”
position and place all the other
switches in the “OFF”position
before replacing the blown
bulbs.
3. If you need assistance replacing any bulbs, contact
your dealer.
Turn Signals
The flasher unit activates both the
turn signal circuits and the hazard
circuit. Should a lamp burn out, 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
268 Vehicle Care
flasher unit will continue to operate.
Check the turn signal lamps visually
before the vehicle is used.
Bulb Wattage
{Warning
Using bulbs with a wattage other
than that specified could cause
the bulb or the wiring to become
hot. This could result in the
warping of the lens and case, and
it could also lead to the outbreak
of fire.
Bulbs are hot immediately after
they go out. When replacing the
bulbs, avoid being burned by
making sure they are fully cooled.
Never drive the vehicle with the
bulbs not working. This could
result in an accident.
You and others could be seriously
injured.When one bulb of a pair of lamps,
such as a headlamp blows out, the
other bulb is approaching the end of
its useful life. We recommend that
both be changed at the same time.
For the lamps (lighting equipment)
such as headlamps, inside of the
lens can mist up momentarily when
driving in the rain or during the car
wash. Also, the temperature
difference between inside and
outside of the lamps can sometimes
cause the water condensation
inside the lens. This is not abnormal
because this is the same
phenomenon as the windshield or
door glass fogs up when it rains.
If the mist goes away minutes after
the lamp is turned on, things are
normal.

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
270 Vehicle Care
Headlamps and Front
Turn Signal
Replacing the Headlamps
When the bulb has blown out,
replace it with a bulb of the
specified wattage. Be careful not to
excessively tighten the mounting
screws when replacing the
headlamp bulbs.
Do not replace a bulb with other
than the specified wattage.
Proper aiming of the headlamps is
important to ensure sufficient
illumination of the highway without
blinding other motorists. When
replacing headlamp bulbs, have the
headlamp aim adjusted at your
dealer.
When replacing a bulb, make sure
the light switch is“OFF”.
See Bulb Replacement 0267.
1. Remove the front grille (3).
Remove the screw (4) from the
center of the grille. Push up on
the tabs of the five clips (1) on
the upper side of the grille and
pull the grille toward you to
remove it. Loosen the nuts (2)
for the turn signal light.2. Remove the turn signal lamp.Open the front door. Use a
phillips head screwdriver to
remove the two screws
between the door and the cab.

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 271
3. Tilt the turn signal lamp unitdown toward the front of the
vehicle and remove it.
4. Disconnect the connector (1)for the turn signal lamp from
the socket (2) and then remove
the lamp.
6. Disengage the rubber seals (2)
from the two projections (3) at
the bottom of the headlamp.
Remove the four bolts (1).
7. Disconnect the headlampconnector (5) and the parking
lamp socket (3). Remove the
headlamp assembly.
When removing the headlamp
connector, pull out the
connector while holding the
center portion of the rubber
boot. Otherwise, the headlamp
bulb will be broken.

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
272 Vehicle Care
8. Remove the rubber boot (2).Push the right side of the
clip (1) that holds the bulb (3)
in place and slide it upwards to
disengage the clip.9. Remove the bulb (1) from thesocket (2) and replace with a
new one.
10. After replacing the bulb, reverse steps 1-8 to install.
Do not touch the glass of the bulb
with your hand. Soiling the glass will
cause the bulb to blow out.
When attaching the rubber boot,
press in both the outside and inside
circumference of it. Make sure that
the rubber boot, the headlamp
assembly, and the bulb are securely
installed without any raised section. If the rubber boot is not firmly in
place, water could get inside the
headlamp and lead to a breakdown.
Replacing Parking Lamps
1. Refer to
“Replacing the
Headlamps” and remove the
headlamp assembly.
2. Pull the bulb out from the parking lamp socket and
replace with a new one.