Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Instruments and Controls 83
Caution (Continued)
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) (Diesel Only) 093 and
Engine Coolant 0263.
Diesel Exhaust Fluid
(DEF) Gauge
The DEF gauge is part of the Driver
Information Center (DIC). See
Driver Information Center (DIC)
(Diesel Only) 093.
Seat Belt Reminders
Seat Belt Warning Light
There is a driver seat belt reminder
light on the instrument cluster.
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 Action
1. 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 0281, Jump Starting -
North America 0326, and Engine
Drive Belt Routing 0396.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Instruments and Controls 85
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 EBD
functions. (The ABS warning
light and brake system warning
light will illuminate at the same
time.) See Antilock Brake
System (ABS) Warning Light
0 87.
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
warning light does not go away,
brake inspection and maintenance
should be performed.Check and Corrective Action
1. Check to see that the parking brake has been fully released.
If it has, check the following:
2. For diesel vehicles, 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 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 0275.
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
86 Instruments and Controls
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.
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 4500, 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 (Dextron©
–III) level is
low, the light and warning buzzer
should come on. Do not use brake
fluid in the brake booster reservoir.
Use only Dextron© –III ATF.
4500 models are equipped with a
Back up Electric Vacuum Pump that
will turn on if brake booster vacuum
becomes insufficient.
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
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
166 Driving and Operating
engine is running. If it stays on,
shut the engine off and find the
cause.
2. Look at the engine coolant temperature gauge. If the
gauge reaches the H (HOT)
area, stop the engine and find
the cause of the overheating.
3. Check that the battery warning light has gone out. The light
should go off and stay off at
normal idle speeds. If the light
does not go out or comes on
during normal operation, have
the charging system checked.
4. Check that the brake low vacuum warning light is out
and that the vacuum buzzer is
not sounding. It is normal for
the warning buzzer to sound
for a few seconds after the
engine starts. If the light and
buzzer remain on, do not drive
the vehicle until the cause has
been found and corrected.
5. Look at the brake system warning light. It should be out
when the parking brake is
released and the engine is running. If it stays on, it could
mean that the brake fluid level
is low. Check the brake fluid
reservoir. This condition must
be corrected before moving the
vehicle.
Caution
To reduce the chance of personal
injury and/or vehicle damage due
to engine overheating, never
leave the engine idling without an
alert driver present. If the engine
should overheat, as indicated by
the engine coolant temperature
gauge, immediate action is
required to correct the condition.
Continued operation of the
engine, even for a short time, may
result in a fire.
Starting the Engine
Do not keep the engine control
switch in the START position for
more than about 10 seconds.
Operating the starter for too long
might cause starter and battery
failure or may result in overheating. When the engine does not start,
wait for 20 to 30 seconds and then
turn the engine control switch again.
Before starting the engine sit in the
driver seat, check that the parking
brake is firmly engaged, the selector
lever is in the P or N (P is preferred)
position and the shift indicator also
shows P or N, and firmly press the
brake pedal to start the engine. See
Ignition Positions
0163.
{Warning
Do not keep the starter motor
engaged for more than
10 seconds at a time, or the
starter motor and the battery will
be adversely affected. Also, fire
may occur due to overheating.
Repeat the steps after a 20 to
30 seconds break.
1. Shift your selector lever to P (Park) or N (Neutral). Your
engine will not start in any
other position-that's a safety
Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Driving and Operating 175
Activating High Idle Mode
Follow the below procedure to
activate the high idle mode:1. Set the parking brake.
2. Set the selector lever in P (Park) or N (Neutral) position.
3. Do not press the brake pedal. 4. Press the cruise control main
switch to set it to ON. At this
time, the operation indicating
light will turn to green.
5. Turn and hold the cruise control set switch in the SET
position. After approximately
3 seconds the cruise control
set indicator light will begin to
flash slowly and the engine idle
will increase to 1,200 r/min.
Canceling High Idle Mode
Any of the following actions will
cancel high idle mode.
. The cruise control main switch is
set to OFF.
. The brake pedal is pressed.
. The parking brake is released.
. The selector lever is moved from
P (Park) or N (Neutral) position.
. The accelerator pedal is
pressed, accelerating the engine
beyond the engine speed
threshold.
The cruise set indicator light will
stop flashing and the engine speed
will return to normal.
Engine Checks Before
Operating
Checks Before Operating
Allow the engine to warm up before
placing the engine under heavy load
driving. While the engine is warming
up under light load, the following
checks should be made:
1. Observe the red engine oil pressure warning light. The
light should go out when the
engine is running. If it stays on,
shut the engine off and find the
cause.
2. Look at the engine coolant temperature gauge. If the
gauge reaches the H (HOT)
area, stop the engine and find
the cause of the overheating.
3. Check that the battery warning light has gone out. The light
should go off and stay off at
normal idle speeds. If the light
does not go out or comes on
during normal operation, have
the charging system checked.