2020 CHEVROLET LOW CAB FORWARD check engine

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
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
208 Driving and Operating
Warning (Continued)
driving habits and drive the
vehicle while keeping a proper
distance between vehicles.
ABS does not prevent crashes if
you do not drive safely. Drive the
vehicle at a safe speed.
Install tires of the specified size,
same brand and same tread
design (including winter tires) on
all wheels. If different tires are
installed, the braking distance
becomes longer and directional
control stability of the vehicle
decreases. This is very
dangerous.
Steering during sudden braking
(when the ABS is working) will
feel slightly different than it does
when the brakes are not applied.
Operate the steering wheel
carefully keeping this in mind.
Driving in sand or on a muddy road
may adversely affect the brakes and
ABS sensors. Wash the vehicle to remove sand and mud after
operating the vehicle in sandy or
muddy conditions.
Before washing the vehicle, provide
necessary protection to prevent
water from being splashed on the
ABS components (sensors and
actuators). Especially when using
high-pressure washing, be careful
not to allow water to be directly
sprayed onto the ABS components
and their harness connectors.
These are not signs of ABS
malfunction:
.
Soon after you start the engine
and the vehicle starts moving,
the sound of motor or valve
working may be heard from the
rear of the vehicle or underside
of the cab. This sound is from a
self-check by the ABS system
and is normal. In addition, you
may also feel some vibration if
the brake pedal is pressed at
this time.
. When ABS is operating,
vibration is felt on the brake
pedal and steering wheel and you may hear the system
operating. This is normal when
ABS is properly operating.
. The exhaust brake may release
when ABS is activated and the
exhaust brake is in operation.
. ABS is more likely to be
activated when the brake is
applied during cornering or
driving over a bump. This is
because inside wheels or
wheels that have gone over a
bump tend to lock.
. ABS is not activated immediately
after starting the vehicle. It is
activated only when the vehicle
speed reaches approx. 10 km/h
(6 MPH). ABS operation is
inactive when the vehicle speed
reduces to approx. 5 km/h
(3 MPH).

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
210 Driving and Operating
Warning (Continued)
‐When tire chains are used.
‐ When driving over road
joints or bumps such as
light reflectors on the road.
‐ When driving on a bumpy
road, stone-paved road or
track.
‐ When driving over an iron
plate or manhole lid.
ABS does not work for wheel skid
during a standing start,
acceleration and cornering which
do not involve braking. On a very
slippery icy road, tires may lose
grip and steering wheel operation
may not be able to control the
vehicle's direction, resulting in
very unstable driving. Always
drive the vehicle observing a safe
speed well matched with both
road surface and tire conditions,
and avoid sudden braking. (Continued)
Warning (Continued)
If powerful engine braking is
applied on a very slippery icy
road, the drive wheels may be
locked (the ABS then does not
work), resulting in loss of vehicle
control.
When ABS is activated, a slight
vibration (especially when the
road surface is different between
right and left wheels) and pulling
may be felt on the brake pedal
and steering wheel. In addition,
an operating sound is produced
from the ABS actuators. This
does not indicate any abnormal
condition. Stay calm and operate
the steering wheel properly.
Electronic Braking force
Distribution (EBD)
EBD is a function that uses the ABS
to distribute braking force ideally
between the front and rear wheels
in order to compensate for changes
in load conditions or any shift of the load due to acceleration or
deceleration, thus preventing
premature locking of the rear
wheels.
{Warning
If a problem should occur with the
EBD function, the ABS warning
light and the brake system
warning light will come on
simultaneously.
The rear wheels will lock more
easily if there is a problem with
the EBD function. Have it
checked and serviced at the
nearest dealer as soon as
possible. You and others could be
seriously injured.
When the EBD operates, the brake
pedal may push back slightly or you
may hear a sound similar to that
generated by the ABS when
operational. Neither of them
indicates any abnormal condition.

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 211
Parking Brake
Parking Brake Lever
When parking or stopping your
vehicle, engage the parking brake
and make sure that the vehicle does
not start moving. Avoid parking your
vehicle on a slope as much as
possible and choose a level and flat
place. If parking on a slope is
unavoidable, be sure to set the
parking brake, make sure that the
vehicle does not move, and block
the wheels with chocks for added
safety.
Illumination of the parking brake
warning light does not mean that the
parking brake is fully applied. The
parking brake lever must be fully
engaged.
When you engage the parking brake
lever, air pressure is reduced and all
four wheel brakes are applied.
{Warning
Although the parking brake
indicator light will come on if the
parking brake is engaged while
the engine control switch is in the
ON position, this does not mean
the parking brake is fully
engaged, so always make sure
the lever is fully pulled up.
Never drive the vehicle with the
parking brake set as this will
cause excessive wear, reduce
parking brake effectiveness and
increase fuel consumption.
Choose a flat place where
stopping and parking are
permitted and where the vehicle
will not obstruct traffic.
Remove all dirt from the vehicle's
light lenses and reflectors to
ensure that the vehicle can be
seen from other vehicles. You and
others could be seriously injured.
Avoid parking for long periods with
cargo on the vehicle.
{Warning
Do not use the parking brake
while the vehicle is in motion
except in an emergency. Applying
the parking brake before the
vehicle has stopped can cause
the tires to lock or the vehicle to
spin, possibly causing an
accident. Unless the parking
brake is fully released during
driving, a fault and/or a fire may
result.
If it was necessary to use the
parking brake during driving, be
sure to check afterwards to
determine if any fault or failure
has resulted.

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
212 Driving and Operating
Operation of Parking Brake
The parking brake lever is located to
the right of the driver's seat.
To set the parking brake, completely
stop the vehicle. Then, without
pressing the release button (1), hold
the brake pedal down while pulling
the parking brake lever (2) all the
way up.The parking brake indicator light in
the instrument panel will come on
when the lever is pulled up. Before
you leave the driver's seat, follow
the steps under
“Parking, or Leaving
Driver's Seat”. See Braking0134.
To release the parking brake, hold
the brake pedal down while pushing
the release button of the parking
brake lever and lower the lever. The
parking brake indicator light in the
instrument panel will go out.
The parking brake indicator light is
designed to remind you if the
parking brake is not released when
the engine control switch is on.
If the parking brake warning light
remains on when the parking brake
lever is lowered, a brake failure or a
drop in air pressure may be the
cause.
Check the brake air pressure for
correct level. If the brake air
pressure is low, contact your local
Isuzu Dealer for service.
If you notice the parking brake lever
travel has increased over time, this
means the cable adjustment must be checked by a qualified
technician. Adjustment may be
required due to parking brake shoe
wear. See
Control of a Vehicle
0 130.
Inspection
Pull the parking brake lever slowly
from the fully released position while
counting the clicks produced as the
lever engages ratchet plate notches
to check that it can be raised the
proper amount and the lever is held
firmly.

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
218 Driving and Operating
Exhaust Brake Function
Diesel Vehicles Equipped with
Exhaust Brake-interlocked Cruise
Automatic activation of the exhaust
brake during cruise control driving
suppresses an increase in the
speed on a downhill slope,
decreasing the need for the driver to
apply the regular brake pedal. The
exhaust brake does not activate
when the exhaust brake switch is
turn off.
The maximum slope angle at which
the system can control the vehicle
speed increase is different
depending on the load the vehicle is
carrying.
Automatic Activation and
Automatic Release of Exhaust
Brake
The exhaust brake is engaged when
the vehicle speed exceeds the set
speed on a downhill slope.
The exhaust brake is disengaged
when the vehicle slows down close
to the set.
Fuel
Fuel for Diesel Engines
Diesel Fuel Requirement and
Fuel System
Fuel Requirements
Use of fuels other than ultra
low-sulfur fuel may not conform to
emission regulations.
The fuel supply pump, injector or
other parts of the fuel system and
engine can be damaged if you use
any fuel or fuel additive other than
those specifically recommended by
the dealer.
To help avoid fuel system or engine
damage, pay attention to the
following:
.Some service stations mix used
engine oil with diesel fuel. Some
manufacturers of large diesel
engines allow this; however, for
your diesel engine, do not use
diesel fuel which has been
contaminated with engine oil.
Besides causing engine damage, such fuel can also
affect emission control. Before
using any diesel fuel, check with
the service station operator to
see if the fuel has been mixed
with engine oil.
. Take care not to run out of diesel
fuel. If you do run out of fuel,
you may need to bleed air out of
the supply pump to re-start the
engine after fuel has been filled.
Your vehicle is designed to use
either Number 1-D or Number 2-D
diesel fuel. However, for better fuel
economy, use Number 2-D diesel
fuel whenever possible. At
temperatures below -7 °C (20 °F),
Number 2-D fuel may pose
operating problems (see "Cold
Weather Operation" which follows).
At colder temperatures, use Number
1-D fuel (if available) or use a
"winterized" Number 2-D (a blend of
Number 1-D and Number 2-D). This
blended fuel is usually called
Number 2-D also, but can be used
in colder temperatures than Number
2-D fuel which has not been