automatic transmission CHEVROLET LOW CAB FORWARD 2020 User Guide

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
Driving and Operating 197
Furthermore, the higher the engine
speed, the stronger the creep and
the greater the vehicle's tendency
to move.
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 Lever0205.
Caution
Do not apply water from a
high-pressure washer nozzle
directly to the electric connectors.
(Continued)
Caution (Continued)
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. (Continued)

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
198 Driving and Operating
Warning (Continued)
When you move the selector lever
into D, 2, 1 or R, creep will cause
the vehicle to move.
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.

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
Driving and Operating 199
To start your vehicle:1. Firmly press the brake pedal. After making sure the selector
lever is placed into P or N, that
P or N is shown in the shift
indicator and that the parking
brake lever is fully pulled up,
place the engine control switch
into the ON position.
2. Start the engine and move the selector lever into D for forward
movement, or R for backward
movement while firmly pressing
the brake pedal with your
right foot.
3. Make sure that the shift indicator indicates the correct
gear (D for forward movement,
or R for backward movement),
release the parking brake,
release the brake pedal, and
then gradually press the
accelerator pedal. The vehicle
starts moving as you press the
accelerator pedal further. On a steep slope:
Make sure that the shift indicator
indicates the correct gear (D for
forward movement, or R for
backward movement), check the
area around the vehicle is clear,
release the brake pedal with your
right foot, and then slowly press the
accelerator pedal.
After you feel the vehicle start
moving, gradually release the
parking brake lever and start driving
the vehicle.
When the brake pedal is not
pressed, the shift lock system
operates and the selector lever
cannot be shifted from P to any
other position.
See
Driver Information Center (DIC)
0 70, Starting and Stopping the
Vehicle 0159, Selector Lever 0205,
and Automatic Transmission Shift
Lock Control Function Check 0264. Normal Driving
When you move the selector lever
from P into D, shifting takes place in
the automatic mode. Check that D is
displayed in the shift indicator.
If the automatic transmission fluid
temperature is too low, the
transmission may not initially make
automatic shift to the 4th, 5th, and
6th gear. This condition is normal
and will be resolved as the fluid
temperature rises.
To Accelerate
To accelerate when the accelerator
pedal is pressed further, kickdown
operates and the speed increases.
The transmission will downshift at
speeds below 88 km/h (55 MPH), to
provide greater acceleration.
Kickdown
If you press the accelerator pedal
fully while driving, in accordance
with the current speed the gear
automatically shifts down and the
engine speed rises, enabling
sufficient acceleration. This is called
kickdown.

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
200 Driving and Operating
You can easily accelerate to the
required speed when overtaking
other vehicles or when joining traffic
on a highway. In order to maintain
speed when driving on an uphill
road, as you gradually press the
accelerator pedal the engine may
automatically shift down in
accordance to the current speed
(shifts to a lower speed gear),
increasing the engine speed and
increasing vehicle speed.
Driving Uphill or Downhill
Uphill driving:
With the selector lever in D, if you
press down on the accelerator
pedal, kickdown (change to a low
speed gear) may operate causing
the engine revolutions to suddenly
increase (increasing the speed).Driving for a prolonged duration on
an uphill road with the selector lever
in D may cause the automatic
transmission fluid to overheat.
Drive with the overdrive off switch
ON to keep the engine revolutions
constant to enable smoother driving
with fewer changes in engine
revolutions.

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
Driving and Operating 201
Driving conditionsSelector lever position
Normal uphill road D (overdrive off switch ON)
Steep uphill, steep slope, mountain
road with many sharp curves 2 or 1
Long uphill road 2
Downhill driving:
Do not overuse the foot brake. This
will cause the brakes to overheat,
reducing their effectiveness. On
long downward slopes or sharp
downhill sections of road, use the
engine brake together with the foot
brakes to control the speed.
When the selector lever is in the D
position, you can drive with the
overdrive off switch ON to allow a
gentle engine brake to be applied.
Push the overdrive off switch to the
ON position at speeds below
101 km/h (63 MPH) to increase
engine braking action when
traveling downgrade. You can increase engine braking by
driving with the selector lever in the
2 position.
To apply a stronger engine brake on
sharp downhill sections, shift the
selector lever to the 1 position when
required.
See
Control of a Vehicle 0130.
Driving at Low Speeds for
Sustained Periods
Any low speed applications such as
sweeper, road marking machinery,
trash collectors, highway striping or
moving, etc. require the following
treatment to prevent the automatic
transmission fluid (ATF) from
overheating:
Select 1 position during low speed
operation under 18 km/h (11 MPH). Select 2 position during low speed
operation under 36 km/h (22 MPH).
See
Automatic Transmission Fluid
Temperature Warning Light 066.
To Stop Your Vehicle 1. To temporarily stop the vehicle, press the brake pedal firmly
while the selector lever is in D.
2. Use the parking brake as required. Press the brake pedal
firmly, and firmly apply the
parking brake.
If the vehicle is stationary for a
long time, move the selector
lever into the N or P position.
If the selector lever is kept in
D, the temperature of the
automatic transmission fluid
increases due to heat from the
torque converter.
To ensure reliable brake application,
be sure to use your right foot to
press the brake pedal.
When leaving the driver's seat,
follow the When Parking Your
Vehicle procedure.

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
Driving and Operating 203
When Parking Your Vehicle
The key cannot be removed unless
the selector lever is securely placed
in the P position (key interlock
system). Be sure to place the
selector lever in the P position when
parking the vehicle.
The shift lock system is a system for
safety to prevent incorrect operation
of the automatic transmission. Use it
correctly and drive safely.
If You Cannot Move the Selector
Lever from the P Position
Caution
When the selector cannot be
operated from the P position to
any other position even after
performing the operation below
repeatedly, the shift lock system
may have a failure. Have the
vehicle inspected at your dealer.If you cannot move the selector
lever from the P position after
starting the engine, perform the
following checks:
.
Check that you are firmly
pressing the brake pedal. When
the brake pedal is not pressed,
the shift lock system operates
and the selector lever cannot be
shifted from P to any other
position.
. Check if the area where your
vehicle is parked is not a slope.
. If your vehicle is parked on a
downside slope, the operation of
the selector lever may become
heavy to move. In this case, you
can operate the selector lever
more smoothly by moving the
selector lever towards the front
of the vehicle while pressing the
button. Releasing the Shift Lock in an
Emergency
If moving of the selector lever from
P to another position is still not
possible even after performing the
instructions given in the steps
above, with the brake pedal fully
pressed and the vehicle parked on a
flat surface, carry out the procedure
described under
“If You Cannot
Move the Selector Lever from the P
Position”.

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
204 Driving and Operating
Actions that Can Lead to a Breakdown with an Automatic Transmission
Actions that can lead to a breakdownBreakdown symptoms
Stopping the vehicle on an uphill road with the selector lever in a position
other than R, N, or P, the accelerator pedal pressed, and the brakes not
applied. The transmission fluid overheats.
Continuously pressing the accelerator pedal and brake pedal at the same
time while the vehicle is in a position other than N or P.
Placing the selector lever into any gear with the accelerator pedal pressed
and the engine speed high. The transmission gears are
overloaded.
Placing the selector lever into P before the vehicle has completely stopped. The parking mechanism will be
damaged.
Turning off the engine control switch while driving. The transmission is not properly
lubricated.
Driving with the selector lever in the N position on a long downward slope
(this is dangerous due to the lack of engine brake).

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
Driving and Operating 205
Selector Lever
Move the selector lever (2) to make
a shift into each gear position.
P (Parking) :Used when the
vehicle is parked or when starting
the engine. The P position is to be
used with the parking brake. The P
and N positions are the two
positions in which the engine can be
started.
R (Reverse) : Used when backing
up the vehicle. Bring the truck to a
complete stop before moving the
selector to the R position. N (Neutral) :
Can be used when
starting the engine, but for safety,
get in the habit of starting the
engine in the P position. The N
position is used should it become
necessary to tow your truck.
D (Drive) : The D position is for all
normal forward driving. The system
automatically selects the gear
according to the vehicle speed.
Press the overdrive off switch (3) to
switch to the overdrive ON position
for greater fuel economy.
2 (Second) : May be used when
driving on downhill roads or when
the engine brake is required. Select
the 2 position at speeds below
40 km/h (25 MPH) when traveling
down a moderate grade. Return the
selector to the D position for normal
driving.
1 (Low) : Used on steep downhill
roads or when strong engine
braking is required. Return the
selector to the D position for normal
driving.
{Warning
When pulling away, always
visually check the position of the
selector lever for safety.
Only push the button for gear
selection when necessary.
Pushing the button unnecessarily
may result in unintended gear
selection.
Never move the selector to the P
position when the truck is in
motion.
Do not run the vehicle with the
transmission in neutral. Not only
will the engine brake not function,
but the transmission will also be
damaged. You and others could
be seriously injured.
When repeatedly shifting between
forward and reverse gears for a
multiple-point turn, firmly press the
brake pedal and confirm that the
vehicle is completely stopped before
operating the selector lever.

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
206 Driving and Operating
For safety reasons, the shift lock
system operates to prevent shifting
of the selector lever to any position
other than P unless the brake pedal
is pressed and the starter switch is
in the ON position. When pulling
away, be sure to keep the brake
pedal pressed as you operate the
selector lever. SeeDriver
Information Center (DIC) 070,
Overdrive Off Light 066, Automatic
Transmission 0196, and Automatic
Transmission Shift Lock Control
Function Check 0264.
Overdrive Off
Overdrive Off Switch
Diesel vehicles have two overdrive
gears (5th and 6th). These two high
speed gears provide increased road
speed, low running noise and
outstanding fuel efficiency.
Take advantage of overdrive
whenever possible.
.
Use the overdrive during normal
driving. When driving down long
downhill roads that require the
engine brake, or when driving on mountain roads or through city
centers, release the overdrive.
Doing so will reduce the number
of gear changes making the ride
smoother.
. If your vehicle is traveling at a
speed exceeding
101 km/h (63 MPH), it is not
possible to downshift from 6th
gear to 5th gear.
. If your vehicle is traveling at a
speed exceeding
78 km/h (49 MPH), it is not
possible to downshift from 5th
gear to 4th gear.
Overdrive Off Switch : Under
normal circumstances, press the
overdrive off switch (3) to turn the
overdrive OFF (the overdrive off
indicator light comes on).
Press the switch again to release
the overdrive off (the overdrive off
indicator light goes off). See
Overdrive Off Light 066.

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
Driving and Operating 207
Overdrive Off Indicator Light
Indicator lightFunction Usage conditions
Goes Off. 6-Speed (4-speed + overdrive) automatic
change (Overdrive ON). Use under normal driving conditions.
Comes On. 4-speed automatic change, but no change to
overdrive (overdrive OFF). Used when a light engine brake is required.
Doing so will reduce the number of gear
changes making the ride smoother on roads
that have many hills.
. During cold weather, the
transmission may not shift to the
5th or 6th gear (overdrive) until
the engine warms up.
. Even if the engine is stopped
with the overdrive OFF, the
overdrive will be ON the next
time the engine is started.
Brakes
Antilock Brake
System (ABS)
Wheels may be locked and slip
during sudden braking or braking on
a slippery road surface such as a
snowy road. ABS is a device to
prevent the wheels from locking by
detecting a slippery condition during
braking and securing the directional
stability and handling stability of the
vehicle. ABS only assists in limited
road conditions and will not prevent
a crash if you exceed safe driving
speeds for road conditions. Always
drive safely.
{Warning
The braking distance on slippery
road surfaces is longer than that
on a normal dry paved road even
with an ABS-equipped vehicle. In
addition the braking distance can
be slightly longer in deep snow
and on a gravel road when ABS
is activated. Therefore, always
keep in mind the road condition
and tire condition (type of tires
and worn condition), observe safe
(Continued)