2019 CHEVROLET LOW CAB FORWARD brake

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
76 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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Instruments and Controls 77
out after approximately
three seconds. If the light does not
come on, have it fixed so it will be
ready to warn if there is a problem.
If this warning light stays on more
than three seconds or comes on
while driving, there is a problem in
the Anti-lock Brake System (ABS).
In this case, the ABS stops working
but the brakes still function as
ordinary service brakes.
{Warning
If this warning light comes on
while driving, immediately stop
your vehicle at a safe place well
clear of traffic and take the
following actions.1. Stop the engine.
2. Restart the engine. Check ifthe ABS warning light
comes on and then goes
out. If it does, there is no
problem. The ABS operates
normally.
(Continued)
Warning (Continued)
3. Move the vehicle slowlyforward. Gradually increase
the speed to 15 km/h
(9 mph). If the light goes off,
the ABS is normal.
If the light does not come on or
go out, or comes on frequently,
contact your dealer immediately
and have the system repaired.
Even if a problem has occurred in
the ABS, the brakes will still work
as normal brakes. In this case,
the ABS has no influence on the
operation of the brake system.
See Brake System Warning Light
(Parking Brake Light) 074 and
Antilock Brake System (ABS) 0216.
Exhaust Brake Light
This light comes on when the
exhaust switch is pulled and the
engine is running. See Exhaust
Brake 0222.
Service Transmission
Warning Light
This light comes on briefly when the
engine control switch is in the ON
position, as a check to show the
light is working. It should go out
when the engine is started.

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 91
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 072.
. Brake booster —continuous
beep. See Brake System
Warning Light (Parking Brake
Light) 074.
. Engine overheat —
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 0189 and
Engine Alarm and Automatic
Shutdown 0173.

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
138 Driving and Operating
Driving and
Operating
Driving Information
Driver Behavior . . . . . . . . . . . . . . . 139
Distracted Driving . . . . . . . . . . . . 139
Control of a Vehicle . . . . . . . . . . . 139
Braking . . . . . . . . . . . . . . . . . . . . . . . 143
Steering . . . . . . . . . . . . . . . . . . . . . . 149
Driving on Wet Roads . . . . . . . . 149
Hill and Mountain Roads . . . . . 150
Winter Driving . . . . . . . . . . . . . . . . 151
If the Vehicle Is Stuck . . . . . . . . 153
Emergencies(Troubleshooting) . . . . . . . . . . . 154
Emergencies (Disabled Vehicle) . . . . . . . . . . . . . . . . . . . . . 164
Starting and Operating
New Vehicle Break-In . . . . . . . . . 165
Pedals . . . . . . . . . . . . . . . . . . . . . . . . 166
Ignition Positions . . . . . . . . . . . . . 166
Starting and Stopping theVehicle . . . . . . . . . . . . . . . . . . . . . . 168
Operating Temperature . . . . . . . 171
Winter Cover . . . . . . . . . . . . . . . . . 172
Engine Heater . . . . . . . . . . . . . . . . 172 Engine Alarm and Automatic
Shutdown . . . . . . . . . . . . . . . . . . . 173
Idle Shutdown . . . . . . . . . . . . . . . . 174
High Idle System . . . . . . . . . . . . . 174
Engine Checks Before Operating . . . . . . . . . . . . . . . . . . . 175
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 176
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 177
Running the Vehicle WhileParked . . . . . . . . . . . . . . . . . . . . . . 179
Diesel Particulate Filter
Diesel Particulate Filter . . . . . . . 180
Diesel Exhaust Fluid
Diesel Exhaust Fluid . . . . . . . . . . 189
Automatic Transmission
Automatic Transmission . . . . . . 205
Selector Lever . . . . . . . . . . . . . . . . 214
Overdrive Off . . . . . . . . . . . . . . . . . 215
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 216
Parking Brake . . . . . . . . . . . . . . . . 220
Exhaust Brake . . . . . . . . . . . . . . . . 222
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 223
Fuel
Fuel for Diesel Engines . . . . . . . 227
Biodiesel . . . . . . . . . . . . . . . . . . . . . 228
Cold Weather Operation . . . . . . 230
Water in Fuel . . . . . . . . . . . . . . . . . 231
Running Out of Fuel . . . . . . . . . . 233
Filling the Tank . . . . . . . . . . . . . . . 235
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . 236
Power Take-Off (PTO) . . . . . . . . 237

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
140 Driving and Operating
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.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 141
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)
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 deposits on 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.