brake CHEVROLET LOW CAB FORWARD 2018 Service Manual

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
162 Driving and Operating
The selectable (switch) regeneration
required warning light (amber) will
turn on when regeneration cannot
be completed automatically. Perform
Running or Switch regeneration in
accordance with the proper
procedure. This is to restore DPF
function and is normal.
The exhaust pipe mixes air with the
exhaust gas to lower its temperature
before it leaves the exhaust pipe.
The frequency of regeneration
increases especially under the
following environments:
‐Midwinter.
‐ Continuous low-speed driving for
long hours (The frequency of
regeneration increases
particularly with special
equipment vehicles such as
sweeper vehicles which mainly
travel at low speed. The
frequency of regeneration is
higher as compared to delivery
vehicles which mainly travel at
standard high speed). Automatic regeneration is performed
under normal driving conditions
(DPF soot accumulation status level
5, and in rare cases, may be
performed at continuously
low-speeds for long hours, except
PM level 5); however, the
regeneration required warning light
(amber) may be displayed in the
DIC under the following driving
conditions:
‐
When only low-speed driving at/
under vehicle speed of 15 km/h
(9 MPH) is performed.
‐ When frequent engine start and
stop are performed.
‐ When the engine stops every
time before the engine is
warmed up.
‐ When continuous idling (over
1 hour) is frequently performed.
If the vehicle is stationary with the
engine idling during DPF
regeneration, the exhaust brake or
exhaust throttle operates. Operating
sounds will be heard when the exhaust brake or exhaust throttle is
activated or deactivated. The
sounds do not indicate a fault.
White smoke could be emitted
briefly from the exhaust pipe in the
following situations, but it is not
indicating a fault.
‐
Combustion of PM during DPF
regeneration.
‐ During DPF regeneration of a
new vehicle which has been
driven a certain distance. The
vehicle may not emit white
smoke during its initial operation
when new.
‐ Long continuous idling.
The exhaust brake may
automatically be activated in order
to prevent emission of white smoke
if the engine idles continuously over
an extended period of time.
White smoke may be produced
during switch regeneration; do not
perform switch regeneration in any
poorly ventilated indoor place.
White smoke may be produced
during DPF regeneration when a
new vehicle has been driven a

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 163
certain distance, but this is not a
malfunction. The vehicle may not
emit white smoke immediately after
purchase.
DPF PM Accumulation Level
This green display only indicates
DPF soot accumulation status. The
DIC can display the PM
accumulation level in green. The L
indicates Low accumulation of PM
and the H indicates High
accumulation of PM in the DPF.
As PM accumulation increases
inside the DPF, the DIC will display
additional bars increasing from L to
H to show the approximate level of
PM accumulation. SeeDriver
Information Center (DIC) 082. DPF Regeneration Status
This amber display indicates the
DPF is regenerating. During DPF
regeneration, the DIC can display
the status of PM reduction in amber.
The highest accumulation level bar
will be flashing as indication of the
regeneration process.
As PM levels decrease in the DPF
during the regeneration process, the
DIC will decrease the number of
bars from H to L. See
Driver
Information Center (DIC) 082.
Automatic Regeneration of DPF
The DPF will regenerate itself as
part of normal operation.
The engine control module (ECM)
controls this function based on
several factors including hours of
operation and mileage. When
automatic regeneration starts, the
regeneration in progress indicator
light (amber) is displayed on
the DIC.
During regeneration the engine idle
speed will increase and the exhaust
brake may activate when the vehicle
is idling while stopped or parked.
Regeneration is normally completed
in about 20 minutes. See Driver
Information Center (DIC) 082.
{Warning
To prevent fire, ensure that there
is no combustible material near
the muffler, the DPF or the
exhaust pipe. Also, be careful not
to burn yourself on the hot
exhaust gas. You and others
could be seriously injured.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
164 Driving and Operating
The DPF performs regeneration
automatically when a certain
quantity of PM accumulates in the
filter.
Depending upon running conditions,
however, the regeneration may
sometimes not be completed. In this
case, the regeneration required
warning light (amber) will come on,
so promptly operate the emergency
regeneration according to the
Emergency Regeneration
Procedure. This operation recovers
the function of the DPF. It does not
mean that a breakdown has
occurred.
The engine speed may increase
and the exhaust brake may activate
while the vehicle is stopped with the
engine idling. When this occurs, the
DPF is automatically regenerated.
This does not indicate a failure.
The system generates a sound
during the automatic regeneration
and its cancellation. This does not
indicate a failure.DPF SwitchThe DPF switch is used to burn PM
(regenerate the filter). You can
initiate regeneration when the
regeneration required warning light
or selectable (switch) regeneration
required warning light turns on with
short repeated beeps.
Continuing driving without
performing the regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on.
The DPF then must be repaired at
the nearest dealer.
Emergency Regeneration
Procedure
If the regeneration required warning
light (amber) or selectable (switch)
regeneration required warning light
(amber) turns on the DIC, the DPF
could not satisfactorily complete
automatic regeneration and driver
action is required. If the
regeneration required warning light
(Not selectable (switch)
regeneration warning light) is turned
on, you can choose from Running

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
166 Driving and Operating
{Warning
To prevent a fire, make sure that
there is no flammable material
near the muffler, DPF and
exhaust pipe. Remember that the
temperature of exhaust gases is
high enough to burn you. You and
others could be seriously injured.
Select Switch regeneration
procedure if the Running
regeneration procedure is not
possible, or if the selectable (switch) regeneration required warning light
(amber or red) is displayed on
the DIC.
1. Stop the vehicle at a safe place free of flammable material such
as dead grass, leaves or waste
paper.
2. Move the selector lever into the P position and firmly engage
the parking brake.
3. Let the engine idle. Be sure the accelerator pedal is not
pressed and the PTO switch (if
equipped) is OFF.
4. Press and release the DPF switch.
5. The regeneration required warning light (amber or red) or
selectable (switch)
regeneration required warning
light (amber or red) on the DIC
will turn off and the
regeneration in progress
indicator light will appear.
6. Do not leave the vehicle during the regeneration. Regeneration
normally completes in about
20 minutes. 7. When the regeneration in
progress indicator light (amber)
goes out, regeneration is
completed. Normal driving is
then possible.
If the Switch regeneration is
interrupted, a selectable (switch)
regeneration required warning light
(amber) will appear on the DIC. You
must complete the DPF
regeneration by performing the
Switch regeneration once again as
soon as possible.
If you continue driving too long with
the selectable (switch) regeneration
required warning light (amber)
displayed on the DIC, the message
will change to red. The selectable
(switch) regeneration required
warning light (red) indicates the
DPF filter is nearly full of PM, a
condition which may be damaging
to the filter.
DPF regeneration should be
completed immediately if the
selectable (switch) regeneration
required warning light (red) is
displayed on the DIC.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 167
Continued driving without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Driver Information Center (DIC)
082.
When operating the PTO for a long
time if your vehicle is so equipped,
make sure that the regeneration
required warning light or selectable
(switch) regeneration required
warning light (amber) is not
turning on.
Once the Switch regeneration is
started, it cannot be switched to the
Running regeneration if interrupted.
When the Switch regeneration is
selected, end regeneration in a
single operation if possible.
During the regeneration, the engine
speed may vary, causing the
exhaust brake valve to be
deactivated. However, while the
regeneration in progress indicator
light (amber) appears, regeneration is still taking place, so continue to
perform regeneration until the
message goes off.
The time needed to complete
regeneration differs depending on
the outside temperature.
The exhaust brake or exhaust
throttle is activated during DPF
regeneration. The exhaust brake or
exhaust throttle starting to operate
or being disengaged will produce a
sound, but this does not indicate a
failure.
During regeneration, white smoke
may be temporarily produced from
the exhaust pipe. This results from
combustion of PM, it does not
indicate a failure.
Switch regeneration will complete
earlier immediately after driving than
when the engine is cold.
The engine coolant temperature
may rise during switch regeneration.
Interruption of Switch
Regeneration
If you must interrupt regeneration for
an unavoidable reason, press the
DPF switch again.
The regeneration in progress
indicator light (amber) changes to
the selectable (switch) regeneration
required warning light (amber).
Then, you can drive the vehicle.
If you interrupt regeneration, you
need to perform regeneration again.
Perform switch regeneration
beginning with Step 1 as soon as
possible.
Switch regeneration will be
interrupted in the following
circumstances:
.
Accelerator pedal is pressed.
. Gear-in.
. Vehicle speed is above
0 km/h (0 MPH).
. Engine speed increases.
Operation noise caused by
interruption is louder when pressing
the accelerator pedal than other
operations. This is not a failure.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
168 Driving and Operating
Selectable Regeneration
Procedure
Your vehicle is equipped with
Selectable Regeneration. This
procedure is designed for vehicles
that do not normally operate in
conditions that make automatic
regeneration possible. This function
allows the driver to check the status
of the PM level and, when available,
perform Switch regeneration at a
convenient time for the driver.
Selectable regeneration may only
be performed when no other DPF
message is present on the DIC. Be
sure to follow any DPF messages
present on the DIC to properly
complete a DPF regeneration.
It is recommended to use the
procedure during breaks in PTO
operation (if equipped) and other
low speed applications.{Warning
Do not leave the vehicle during
the regeneration.
Make sure that there are no
flammables near the muffler, DPF
and exhaust pipe which may
result in a fire.
Remember that the temperature
of exhaust gases is high enough
to burn you. You and others could
be seriously injured.
1. Stop the vehicle at a safe place free of flammable material such
as dead grass, leaves or waste
paper.
2. Move the selector lever into the P position and firmly engage
the parking brake.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
170 Driving and Operating
the selectable (switch) regeneration
required warning light (red) is
displayed on the DIC.
Continued driving without
performing DPF regeneration will
cause the check engine malfunction
indicator light and reduced engine
power indicator light to come on, an
engine power reduction, and may
cause damage to the DPF filter. See
Vehicle Messages086.
The time needed to complete
regeneration differs depending on
the outside temperature.
The exhaust brake is activated
during DPF regeneration. The
exhaust brake starting to operate or
being disengaged will produce a
sound, but this does not indicate a
failure.
During regeneration, white smoke
may be temporarily produced from
the exhaust pipe. This results from
combustion of PM, it does not
indicate a failure.
Regeneration is finished earlier
immediately after driving than when
the engine is cold. The engine coolant temperature
may rise during regeneration.
DPF Regeneration during
Prolonged Idling
DPF regeneration may be initiated
automatically during prolonged
idling. If regeneration is initiated, the
regeneration in progress indicator
light (amber) comes on but this is
normal and does not indicate a
failure.
If driving is started or the PTO is
connected during DPF regeneration
by prolonged idling, the selectable
(switch) regeneration required
warning light (amber) comes on and
regeneration is suspended. Perform
Switch regeneration procedure in
order to complete the DPF
regeneration.
Prolonged idling may require more
frequent DPF regeneration.
See
Driver Information Center (DIC)
0 82.Diesel Exhaust Fluid
Diesel exhaust fluid (DEF) is used
exclusively for the selective catalytic
reduction (SCR) system. Be sure to
use only API certified DEF. When
the SCR system detects DEF level
is nearly empty or incorrect fluids
(such as water or low concentrated
DEF.) are added, the SCR system
will turn on warning and indicator
lights and reduce engine power in
progressive stages to encourage
you to have the condition corrected.
Continuing to drive for too long after
these lights come on will eventually
result in a severe vehicle speed
limitation. See Vehicle Messages
0 86
The DEF freezes below −11 °C
(12 °F). The SCR system is
equipped with a heating function
which utilizes the engine coolant, so
the engine can be started even
when DEF is frozen.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
11254764) - 2018 - crc - 12/5/16
Driving and Operating 185
When the exhaust system warning
light comes on, promptly have the
vehicle inspected and serviced at a
dealer.
When a malfunction is detected in
the SCR system, the warning and
the indicator lights shown in the
table come on. SeeVehicle
Messages 086, Malfunction
Indicator Lamp (Check Engine
Light) 074, and Diesel Exhaust
Fluid (DEF) Warning Light 080.
When the Diesel Exhaust Fluid
(DEF) Tank is Empty
If the DEF tank is empty and
warning and indicator lights are on,
you must follow below procedure to
cancel the vehicle restriction: 1. Turn the engine control switch to the LOCK or ACC position,
and add DEF.
2. After adding DEF, turn the engine control switch to ON
position.
3. Wait until buzzer stops, warnings and indicators are
turned off. 4. If the buzzer does not stop,
return the engine control switch
back to the LOCK position and
add more DEF, and then start
over from step 2 above.
5. Restart the engine.
It may take a while until the warning
lights and indicators turn off and the
buzzer stops after turning the
engine control switch to the ON
position.
It is desirable to fill up the tank with
DEF to avoid DEF remaining level
warning indication from reappearing.
When the outside temperature is
low, refer to Adding DEF in Cold
Weather. See Driver Information
Center (DIC) 082, Brake System
Warning Light (Parking Brake Light)
0 75, Warning Buzzers 091, and
Winter Driving 0133.Automatic
Transmission
On an automatic transmission
vehicle, the driver does not use a
clutch pedal when pulling away,
changing gears, or stopping. Only
the selector lever, accelerator pedal,
and brake pedal are used.
Practice learning the characteristics
of the automatic transmission
vehicle and how to correctly operate
it. When the vehicle is stationary,
remember to keep the brake pedal
firmly pressed, and if necessary,
move the selector lever in the P or
N position and apply the parking
brake.
Creep : With the engine running
and a gear position other than P or
N selected with the selector lever,
power reaches the wheels even
when the accelerator pedal is not
pressed, causing the vehicle to tend
to move.
Furthermore, the higher the engine
speed, the stronger the creep and
the greater the vehicle's tendency
to move.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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186 Driving and Operating
Starting
Start the engine in either the P or
the N position. The engine should
not start in any other selector
position. If it does, something is
wrong. Have your truck checked by
your dealer as soon as possible.
Always apply either the foot brake
or the parking brake before shifting
into any driving position. This will
prevent creeping.
The engine should be running at
idle when shifting from P or N to one
of the driving positions. See
Selector Lever0194.
Caution
Do not apply water from a
high-pressure washer nozzle
directly to the electric connectors.
Failure to observe this precaution
can lead to faulty operation of the
electrical system.
Caution
Never move the selector into the
P position when the vehicle is in
motion. This will damage the
automatic transmission.
Firmly press the brake pedal to
prevent the vehicle from moving
even if it is stopped on a level road,
and move the selector lever into P
and firmly apply the parking brake
as needed.
The engine speed rises and
creeping will be stronger than usual
during the conditions noted below.
Keep the brake pedal firmly
pressed:
. Immediately after engine
start up.
. While the air conditioner is
running.
. During the diesel particulate filter
(DPF) regeneration. How to Use the Automatic
Transmission{Warning
Before starting the engine, move
the selector lever into P or N (P is
preferred), make sure the shift
indicator indicates P or N, pull up
the parking brake lever and firmly
press the brake pedal.
When moving the selector lever to
any position other than P, be sure
to press the brake pedal.
Never leave the driver's seat with
the selector lever placed in D, 2,
1 or R. The vehicle may start
moving. When leaving the driver's
seat, be sure to move the selector
lever into P and securely set the
parking brake.
When you move the selector lever
into D, 2, 1 or R, creep will cause
the vehicle to move.
(Continued)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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Driving and Operating 187
Warning (Continued)
When pulling away from a
standstill, you must control the
speed using only the accelerator
pedal. Operate the accelerator
pedal carefully.
Do not operate the selector lever
while pressing the accelerator
pedal. The vehicle may make a
sudden start, possibly causing an
accident.
You and others could be seriously
injured.
When pulling away, visually check
the position of the selector lever.
If you always press the push button
while operating the selector lever,
the lever may occasionally move to
the other gear position against your
intentions.
Practice operating the selector lever
between the N and D without
pressing the push button. Do not operate the selector lever
while pressing the accelerator
pedal. Doing so is dangerous
because the vehicle would
suddenly move.
Do not operate the automatic
transmission at or near stall
condition for more than
five seconds. Stall condition is when
the transmission is in one of the
driving ranges, the engine is running
at high speed, but the drive wheels
are unable to move. This condition
might occur if the vehicle is stuck in
deep sand or is pushing against a
fixed barrier. Operating the
transmission at stall condition will
result in overheating and damage.
Do not hold your vehicle on an
upgrade with the accelerator pedal.
Doing so will result in automatic
transmission overheating and
damage. Use the parking brake or
foot brake to hold the vehicle on an
upgrade.
Even if you plan to move only a
short distance, sit in the correct
driving position and make sure you
can firmly press the brake and
accelerator pedals.
When you reverse, you twist to look
rearward so pedal operation
becomes difficult. Firmly press the
brake pedal. Also, practice returning
the selector lever immediately to the
N position after reversing. When
pulling away, visually check the
selector lever position and the shift
indicator.
When the vehicle is stopped, do not
keep pressing the accelerator pedal
with the selector lever in a forward
gear or R position while pressing
the brake pedal. Doing so may
cause a breakdown.
Sit in the correct driving position,
and use your right foot to operate
the brake and accelerator pedals.
To avoid accidentally pressing the
wrong pedal, check the pedal
positions and practice putting your
foot on the desired pedal.