2019 CHEVROLET LOW CAB FORWARD check engine

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
220 Driving and Operating
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 221
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 Braking0143.
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
0 139.
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 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
228 Driving and Operating
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.
. Do not use any fuel additive
(other than as recommended
under "Biocides" in Water in
Fuel 0231). At the time this
manual was printed, no other
fuel additive was recommended.
(See your authorized dealer to
find out if this has changed.)
. 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
"winterized". Check with the service
station operator to be sure you get
the properly blended fuel.
Do not use fuels other than those
recommended in this manual. Doing
so may adversely affect the engine.
DIESEL FUEL/APPLICABLE
STANDARD (Sulfur content below 15ppm)
ASTM
(AMERICAN
SOCIETY FOR
TESTING and
MATERIALS) Based on D975
Number 1–D
S15 or Number
2-D S15 (below
15 ppm)Biodiesel
Biodiesel, may also be referred to
as FAME blended (Fatty-acid methyl
ester) fuel is a renewable fuel
produced from vegetable oils or
animal fats that have been
chemically modified to make it
compatible with diesel fuel.
Caution
Do not use home-made biodiesel
or home test kits because the
quality cannot be verified by
approved scientific methods. Do
not use raw vegetable oil or other
unmodified bio-oils, fats,
or blends of vegetable oil with
diesel. They could damage the
fuel system and engine, and
damages would not be covered
by the vehicle warranty.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
232 Driving and Operating
from your dealer, service stations,
parts stores and other automotive
places. See your authorized dealer
for advice on using biocides in your
area and for recommendations on
which biocides you should use.
Smoke Suppressants
Because of extensive testing of
treated fuel versus untreated fuel,
the use of a smoke suppressant
additive is not recommended
because of the greater possibility of
stuck rings and guttered valves,
resulting from excessive ash
deposits.
Water Separator
The purpose of the water separator
is to separate any water from the
fuel that may have formed in the
fuel tank due to condensation.
The water separator is located on
the bottom of the fuel filter.
Caution
Remaining water that is not
discharged from the water
separator could freeze and
damage the vehicle.
If the warning light comes on
while the engine is in operation,
promptly drain the water from the
water separator (fuel filter).
Continuing to drive with the light
remaining on could damage the
fuel injection system. If this
happens, have the vehicle
checked and serviced by the
nearest dealer.
Draining Water from the Fuel
Filter
Clean off any fuel that has adhered
to the vehicle body.
Starting the engine immediately
after draining the water from the fuel
filter requires a little more time than
usual. If the engine does not start in
10 seconds, wait for a while and try
again.Fuel will be mixed in the drained
water. Dispose of it in a method
conforming to the regulatory
requirements in your state.
If the water separator (fuel filter)
requires frequent draining, have the
fuel system inspected at your
dealer.Pre Fuel Filter (Chassis-side)
1. Attach a plastic hose to the drain plug (2) on the bottom of
the chassis-side fuel filter and
put the other end of the hose in
a container placed beneath the
filter.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 233
2. Loosen the drain plug andmove the priming pump (1) up
and down by hand between
10 and 20 times.
3. Fully tighten the drain plug (2) and move the priming pump (1)
several times.
Fuel Filter (Engine-side)
1. Attach a plastic hose to the drain plug (2) on the bottom of
the engine-side fuel filter (1)
and put the other end of the
hose in a container placed
beneath the filter.
2. Loosen the drain plug andmove the priming pump up and
down by hand between 10 and
20 times.
3. Fully tighten the drain plug and move the priming pump several
times.
4. Test run the engine and check that there are no fuel leaks
from the drain plug of the
engine-side fuel filter. Also
check that the water separator
(fuel filter) warning light
stays off.
Running Out of Fuel
When the Fuel Tank is Empty
When the fuel tank is empty, air will
enter the fuel system, so refueling
alone will not be enough to restart
the engine. Use the following
methods to bleed the fuel system.
Bleeding the Fuel System
Steps for Refueling
1. Follow the directions in "Parking Brake Lever" under
Parking Brake 0220.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
234 Driving and Operating
2. Select the correct fuel (See"Diesel Fuel Requirement and
Fuel System"). Follow any
posted safety rules. Stand to
the side, never above or
opposite the filler opening.
3. Check that the fuel cap is tight, and see to it that engine oil,
engine coolant in the reservoir,
and washer fluid, etc. are at
proper levels. Then do the
Driver Daily Checklist.
See Owner Checks and Services
0 340.
Driving your vehicle until the fuel
tank is empty may activate the
check engine malfunction indicator
light. You do not need to have your
vehicle checked. After refueling,
perform the following:
. Bleed the fuel system.
. Start, turn off and restart the
engine three or four times.
. The check engine malfunction
indicator light will be cancelled. Before Starting the Engine
1. The priming pump (1) is
located on the outboard side of
the left frame rail, in front of the
batteries. Place a container
beneath the air bleed plug (2)
to receive fuel, and then fully
loosen the plug.
2. Attach a clear hose onto the air bleed plug, direct the clear
hose into a catch pan.
3. Pump the priming pump (1) up/ down for 65 times to get most
of the air bubbles out. Note fuel
was drawn into the filter bowl at
around 40 - 50 times. 4. Fully retighten the air bleed
plug (2) and wipe off any fuel
that may have adhered to the
plug or surrounding area.
5. Continue to operate the pump for 50 times.
6. Start the engine.
7. If the engine does not start, repeat steps 5 and 6 as
necessary until it does start.
After Starting the Engine 1. Without pressing the accelerator pedal, start the
engine.
2. After the engine has started, allow it to idle for about
5 seconds.
3. Fully press the accelerator pedal and increase the engine
speed to the maximum speed
for 10 seconds. (Repeat this
operation several times.)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Driving and Operating 237
and other systems, resulting in a
vehicle breakdown or in a
malfunction of electronic equipment.
Consult your dealer if you wish to
install radio equipment.
Power Take-Off (PTO)
If equipped, the PTO is a device
that is used to provide engine power
to special equipment directly from
the engine or through the
transmission. For details about the
PTO operation, refer to the separate
instruction manual provided by its
maker.
If the optional PTO function is used
for long periods of time, make sure
to regularly check the diesel
particulate filter (DPF) indicator.
Automatic DPF regeneration will not
take place while the PTO function is
active.
1. Engine Speed ControlSwitch
2. Main Switch
{Warning
In PTO mode, Cruise Set/Resume
Switch can be used exactly the
same as PTO Engine Speed
Control Switch. Improper
operation of these switches may
cause personal injury or damage.
When Operating the PTO
For operation of special equipment,
see the manufacturer ’s instructions.Installations, or alterations to the
original equipment vehicle or
chassis, as manufactured and
assembled by General Motors, are
not covered by this warranty. The
body company, assembler,
or equipment installer is solely
responsible for warranties on the
body or equipment and any
alterations to any of the parts,
components, systems,
or assemblies installed by GM.
Examples include, but are not
limited to, special body installation,
such as recreational vehicles, the
installation of any non-GM part,
cutting, welding, or the
disconnecting of original equipment
vehicle or chassis parts and
components, extension of the
wheelbase, suspension, and
driveline modifications, and axle
additions.
The engine control module (ECM)
has the ability to accommodate one
of three different PTO modes. Each
mode can be programmed to
accommodate many PTO devices.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500/5500 Series (GMNA-
Localizing-U.S.-12407814) - 2019 - crc - 12/13/17
Vehicle Care 239
Vehicle Care
General Information
General Information . . . . . . . . . . 240
California Proposition65 Warning . . . . . . . . . . . . . . . . . 240
California Perchlorate Materials Requirements . . . . . 240
Accessories and Modifications . . . . . . . . . . . . . . . . 240
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 241
Cab Tilting . . . . . . . . . . . . . . . . . . . . 243
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 244
Engine Cover . . . . . . . . . . . . . . . . . 245
Engine Oil . . . . . . . . . . . . . . . . . . . . 245
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . 251
Engine Air Cleaner/Filter . . . . . . 253
Engine Coolant . . . . . . . . . . . . . . . 253
Engine Overheating . . . . . . . . . . 259
Power Steering Fluid . . . . . . . . . 262
Washer Fluid . . . . . . . . . . . . . . . . . 262
Brakes . . . . . . . . . . . . . . . . . . . . . . . 263
Brake Fluid . . . . . . . . . . . . . . . . . . . 268
Battery - North America . . . . . . 269 Fuel Filter . . . . . . . . . . . . . . . . . . . . 270
Rear Axle (Gear Oil Viscosity
Chart) . . . . . . . . . . . . . . . . . . . . . . . 271
Rear Axle (Oil Level Check) . . . . . . . . . . . . . . . . . . . . . . 272
Noise Control System . . . . . . . . 272
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 274
Wiper Blade Replacement . . . . 275
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 277
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 277
Headlamps and Front Turn Signal . . . . . . . . . . . . . . . . . . . . . . . 280
Roofmarker Lamps . . . . . . . . . . . 284
Sidemarker Lamps (Including Turn Signal and Cornering
Lamps) . . . . . . . . . . . . . . . . . . . . . . 284
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 286
License Plate Lamp . . . . . . . . . . 286
Interior Lamps . . . . . . . . . . . . . . . . 287
Electrical System
Electrical System Overload . . . 287
Wheels and Tires
Wheels and Tires . . . . . . . . . . . . . 295
Tire Pressure . . . . . . . . . . . . . . . . . 307
Tire Rotation . . . . . . . . . . . . . . . . . 307
If a Tire Goes Flat . . . . . . . . . . . . 310
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . 311
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . 315
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . 317
Interior Care . . . . . . . . . . . . . . . . . . 323