Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Instruments and Controls 77
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
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.
This warning light comes on
together with the brake system
warning light whenever 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)
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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78 Instruments and Controls
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) 075 and
Antilock Brake System (ABS) 0196.
Exhaust Brake Light
This light comes on when the
exhaust switch is pulled and the
engine is running. See Exhaust
Brake 0201.
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. If the warning light starts to blink
while driving, it indicates that there
is a malfunction in the automatic
transmission’s electronic control
system. If the warning light is
blinking, see your dealer for service.
Automatic Transmission
Fluid Temperature
Warning 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.
The Automatic Transmission Fluid
(ATF) Temperature warning light
comes on if the ATF temperature is
high. This usually occurs when the
transmission is overfilled and may
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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82 Instruments and Controls
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.
SeeExterior Lamp Controls 092.
Cruise Control 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.
For vehicles with cruise control, this
light comes on when cruise control
is turned on.
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.
This light comes on when the
vehicle enters the cruise control
mode after the cruise control set
switch is operated to set the vehicle
speed.
See Cruise Control 0202.
Information Displays
Driver Information
Center (DIC)
The DIC display is in the center of
the instrument cluster. The displays
show the status of many vehicle
systems. There are three parts to
the DIC display:
1. DIC menu items and warning lights and messages (includes
operation related information,
diesel particulate filter (DPF)
status, maintenance data, and
errors)
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Instruments and Controls 91
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:
.Seat belt —continuous beep.
See Seat Belt Reminders 073.
. Brake booster —continuous
beep. See Brake System
Warning Light (Parking Brake
Light) 075.
. 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 0170 and
Engine Alarm and Automatic
Shutdown 0155.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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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 stopped.
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 082 and Turn and
Lane-Change Signals 094.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 121
Driving and
Operating
Driving Information
Driver Behavior . . . . . . . . . . . . . . . 122
Distracted Driving . . . . . . . . . . . . 122
Control of a Vehicle . . . . . . . . . . . 122
Braking . . . . . . . . . . . . . . . . . . . . . . . 126
Steering . . . . . . . . . . . . . . . . . . . . . . 131
Driving on Wet Roads . . . . . . . . 132
Hill and Mountain Roads . . . . . 132
Winter Driving . . . . . . . . . . . . . . . . 133
If the Vehicle Is Stuck . . . . . . . . 136
Emergencies(Troubleshooting) . . . . . . . . . . . 137
Emergencies (Disabled Vehicle) . . . . . . . . . . . . . . . . . . . . . 146
Starting and Operating
New Vehicle Break-In . . . . . . . . . 147
Pedals . . . . . . . . . . . . . . . . . . . . . . . . 148
Ignition Positions . . . . . . . . . . . . . 148
Starting and Stopping theVehicle . . . . . . . . . . . . . . . . . . . . . . 149
Operating Temperature . . . . . . . 153
Winter Cover . . . . . . . . . . . . . . . . . 154
Engine Heater . . . . . . . . . . . . . . . . 154
Engine Alarm and Automatic Shutdown . . . . . . . . . . . . . . . . . . . 155 Idle Shutdown . . . . . . . . . . . . . . . . 155
High Idle System . . . . . . . . . . . . . 155
Engine Checks Before
Operating . . . . . . . . . . . . . . . . . . . 156
Parking over Things
That Burn . . . . . . . . . . . . . . . . . . . 157
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 159
Running the Vehicle WhileParked . . . . . . . . . . . . . . . . . . . . . . 160
Diesel Particulate Filter
Diesel Particulate Filter . . . . . . . 161
Diesel Exhaust Fluid
Diesel Exhaust Fluid . . . . . . . . . . 170
Automatic Transmission
Automatic Transmission . . . . . . 185
Selector Lever . . . . . . . . . . . . . . . . 194
Overdrive Off . . . . . . . . . . . . . . . . . 195
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 196
Parking Brake . . . . . . . . . . . . . . . . 200
Exhaust Brake . . . . . . . . . . . . . . . . 201
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 202
Fuel
Fuel for Diesel Engines . . . . . . . 206
Biodiesel . . . . . . . . . . . . . . . . . . . . . 207
Cold Weather Operation . . . . . . 209
Water in Fuel . . . . . . . . . . . . . . . . . 209
Running Out of Fuel . . . . . . . . . . 212
Filling the Tank . . . . . . . . . . . . . . . 213
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . 215
Power Take-Off (PTO) . . . . . . . . 215
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Driving and Operating 123
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 other accident by acting as
lenses.
You and others could be seriously
injured.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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124 Driving and Operating
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.
When the Silencer and
Exhaust Pipe are Hot
{Warning
When the engine is running and
immediately after vehicle
operation, the DPF, silencer, and
(Continued)