check engine CHEVROLET LOW CAB FORWARD 2017 Owner's Manual

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
276 Vehicle Care
Follow the recommendations for
brake checks in the Maintenance
Schedule.
GM replacement brake lining
material is recommended for this
vehicle to maintain the balance
between front and rear brake
performance. GM replacement
brake parts have been carefully
selected to provide the proper brake
balance for purposes of both
stopping distance and controllability
over the full range of operating
conditions. Installation of front or
rear brake lining material with
performance different from that of
the replacement parts
recommended for this vehicle can
change the intended brake balance
of this vehicle.
Checking the Brake Electric
Vacuum Pump (4500HD/
4500XD Series)
1. Turn the engine control switchto the "ON" position (do not
start the engine), and press the
brake pedal several times. 2. Check for the noisy sound of
the electric vacuum pump
inside the instrument panel at
the same time as vacuum
warning buzzer sound, and
check that the brake low
vacuum warning light
comes on.
3. Then, start the engine. The main vacuum pump driven by
the engine will start running.
If the electric vacuum pump
operation (noisy sound) and
the vacuum warning buzzer
stop, and the brake low
vacuum warning light goes off
thereafter, the operation is
normal.
4. If you cannot hear the noisy sound or the noisy sound stays
on all the time, have the
vehicle inspected by the
nearest dealer immediately.Hydraulic Brake Booster (HBB)
The 5500HD, 5500XD models are
equipped with a HBB system. HBB
is a brake booster device that utilizes hydraulic pressure from the
HBB pump integral with the power
steering pump.
If the brake booster warning light
comes on or a warning buzzer
continues to sound, there may be a
problem with the HBB.
If this warning light comes on while
driving, immediately stop your
vehicle at a safe place well clear of
traffic and promptly contact the
nearest dealer for inspection.
Hydraulic brake booster (HBB)
characteristics
In the 5500HD, 5500XD models, an
unusual sound from under the
instrument panel may be heard from
the hydraulic system while brakes
are used. It does not mean trouble.
It is not a sign of malfunction.
If you pump the brakes with the
engine off, a squeaking sound can
be heard. This comes from the
auxiliary accumulator. It is not a
malfunction. With the engine
running, a similar sound can be
heard during sudden braking.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
278 Vehicle Care
major brake problems. As such,
mixing of these two fluids can
ultimately lead to vehicle fire or
other serious accidents.
When the pump operates while the
engine is running, the fluid in the
hydro- booster will become hot.
During normal braking, the
temperature in piping and within
the hydro-booster can rise above
100 °C (212 °F). For this reason,
special care will be required when
working with hydro-booster
components. If the hydro- booster is
to be removed from the vehicle,
shut off the engine and then allow at
least 30 minutes for it to cool down
before beginning this operation.
Even when the engine is stopped,
the hydro-booster's accumulator will
remain in a highly-pressurized
condition for a significant period of
time. Before removing the
hydro-booster or piping from the
vehicle, stop the engine and
depress the brake pedal at least 10
times in order to lower the
accumulator pressure to
atmospheric pressure. This is of
particular importance whenremoving components such as the
accumulator or pressure switch from
the hydro-booster. If these
operations are attempted while the
accumulator is still at a high
pressure, hydro-booster fluid may
spray out.
Checking the Hydro-booster Fluid
Level
Check the hydro-booster fluid level
and change the fluid according to
the Maintenance Schedule.
The hydro-booster fluid level is
correct if it is between the "MAX"
and "MIN" lines. If the level is too
low, add fluid up to the "MAX" line.
Be sure to use ATF Dexron
®-VI fluid
when adding fluid. The brake
booster reservoir is located behind
the cab on the left side.
Brake Pedal
Stroke
Shut off the engine and press the
brake pedal about 10 times strongly,
then check the brake pedal for free
play by lightly pushing it by hand
until you feel resistance.
Free play (measured at the tip of pedal)
4 - 7 mm (0.16 - 0.28 in) (3500/4500)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 279
5 - 10 mm (0.20 - 0.39 in)
(3500HD/4500HD/4500XD)
24 - 29 mm (0.95 - 1.14 in) (5500HD/5500XD)
1. Clearance from the floor.
2. Brake pedal bracket.
Next, start the engine, and wait at
least 1 minute. Then press the
brake pedal and measure the
clearance (1) of the pedal from the
floor (that is, the distance between
the brake pedal bracket (2) and the
brake pedal arm). Clearance between the brake
pedal and the brake pedal bracket with a pressure of 490 N (110 lbs)
applied to the brake pedal
35 mm (1.38 in) or more (3500HD/ 4500HD/4500XD)
45 mm (1.77 in) or more (3500/4500)
Clearance between the brake
pedal and the brake pedal bracket
with a pressure of 294 N (66 lbs) applied to the brake pedal
45 mm (1.77 in) or more (3500/4500)
35 mm (1.38 in) or more (3500HD/ 4500HD/4500XD/5500HD/ 5500XD)
If, after continued pressing of the
brake pedal, the clearance slowly
decreases or the pedal action feels
spongy, air may be trapped in the
brake hydraulic circuit. Have your
vehicle inspected at the nearest
dealer as soon as possible. If your vehicle's brakes squeak
during normal driving or braking, the
cause may be one of the following.
‐
Brake pad wear
Brake pads are about to wear
out. If this happens, have your
vehicle inspected at the nearest
dealer as soon as possible.
‐ Adherence of sand, grit or mud
If sand, grit or mud adheres to
the brakes, a screeching sound
may be emitted upon contact with
rotating components. If this
happens, wash the vehicle to
remove all such adhering matter.
If cleaning alone does not
eliminate the squeaking sound,
have your vehicle inspected at
the nearest dealer.Brake Hoses and Pipes
Inspection
With the steering wheel turned fully
to the left, check the left front brake
hose and pipe visually and by
touch, making sure that they are
free of scratches, cracks and
bulging. Also make sure that the

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 281
Never mix the specified brake fluid
with fluids of another brand.
Be careful not to spill brake fluid
onto painted surfaces or to let it
come in contact with skin. If fluid is
spilled onto a painted surface or
comes in contact with skin, wash
away the fluid with water and
immediately wipe the area clean.
Brake fluid readily absorbs moisture.
Therefore, it is necessary to close
the brake fluid container tightly for
storage.
If the brake fluid level decreases
rapidly, there may be a problem in
the brake system or brake pads or
shoe linings may have worn out.
Have your vehicle inspected by the
nearest dealer immediately.Battery
Working Near Battery
Diesel Vehicle Shown, GasolineVehicle Similar
The batteries are located on the
outboard side of the left frame rail,
behind the cab. The batteries are in
a carrier with the cover (2) retained
by spring clips (1).
{Danger
Follow the precautions listed in
the jump starting Danger (see
"When the Battery is Discharged")
when working on or near the
battery. Personal injury
(particularly to eyes) or property
damage may result from battery
explosion, battery fluid or
electrical (short circuit) burns. You
and others could be seriously
injured or killed.
If the negative cable is disconnected
from the negative terminal on the
battery within 3 minutes after turning
the engine control switch to the
"LOCK" position, the engine control
module may malfunction.
Checking the Battery
Your new vehicle is equipped with
DELKOR (Diesel vehicles) or
CHAMPION (Gasoline vehicles)
batteries. They need no periodic
electrolyte level maintenance. Its
top is permanently sealed (except
for two small vent holes) and has no

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
282 Vehicle Care
filler caps. You will never have to
add water. Remember to check and
recharge the battery as necessary,
as well as keep connection clean.
The hydrometer (green-eye test
indicator) in the top of each battery
(if equipped) provides information
for testing purposes only.
If the vehicle is not going to be
driven for 30 days or longer,
disconnect the ground cable from
the negative (–) terminal of the
batteries to prevent discharge.
For full power needs at replacement
time, a battery with the same
specifications, as shown on the
original battery's label, is
recommended.
{Warning
Battery posts, terminals and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive(Continued)
Warning (Continued)
harm. Wash hands after handling.
You and others could be seriously
injured.
Fuel Filter
Change the fuel filter in accordance
with the Maintenance Schedule or
when the fuel filter indicator light
(amber) comes on.
Drain the water when the water
separator (fuel filter) warning light
comes on. (Drain the water from the
chassis-side fuel filter and
engine-side fuel filter.)
Failure to replace the fuel filter when
needed may lead to fuel system
damage. Your authorized dealer can
inspect your fuel filter and replace
your fuel filter, if needed.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 285
Engine:
Removal or rendering engine speed
governor, if so equipped, inoperative
so as to allow engine speed to
exceed manufacturer specifications.
Fan and Drive:
.Removal of fan clutch or
rendering clutch inoperative.
. Removal of the fan shroud.
Air Intake:
. Removal of air cleaner silencer.
. Reversing air cleaner cover.
Exhaust:
. Removal of muffler, catalytic
converter, and/or resonator.
. Removal of exhaust pipes and
exhaust pipe clamps.
. For diesel vehicles, removal or
modification of diesel particulate
filter (DPF).
. For diesel vehicles, removal or
modification of selective catalytic
reduction (SCR) catalyst.Automatic Transmission
Shift Lock Control
Function Check
(Diesel Only)
When the Selector Lever
Cannot be Moved From the "P"
Position
Perform the following when the
selector lever cannot be moved from
the "P" position.
When performing the below
operations, make sure the parking
brake is securely engaged.
1. Securely pull the parking brake lever and stop the engine.
2. Remove the cup holder (1) byremoving the three Torx®
bolts (2).

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
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288 Vehicle Care
2. Continue pushing in the wiperrubber insert until the wiper
blade's hook engages with the
hole in it, and then confirm that
the rubber insert is securely
held in place.
3. Attach the wiper blade to the wiper arm.Headlamp Aiming
For vertical aiming, turn the two
screws indicated by arrows in the
diagram.
1. Remove the rubber beneath the headlight.
2. Two screws should be turned in the same direction at the
same time to adjust aiming.
3. When the headlamp aiming is out of position, contact your
dealer.
Bulb Replacement
Bulbs
1. Check each bulb for blowout.
2. If a bulb has blown out, replaceit. Always place the engine
control switch in the “LOCK”
position and place all the other
switches in the “OFF”position
before replacing the blown
bulbs.
3. If you need assistance replacing any bulbs, contact
your dealer.
Turn Signals
The flasher unit activates both the
turn signal circuits and the hazard
circuit. Should a lamp burn out, the
flasher unit will continue to operate.
Check the turn signal lamps visually
before the vehicle is used.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
314 Vehicle Care
Checking Tires
Air Pressure
Too low or too high a tire air
pressure not only affects the ride or
causes damage to the cargo but
also causes abnormal heat buildup,
premature wear, a tire puncture,
or may even cause the tire to burst.
Use an appropriate tire air pressure
gauge when measuring the air
pressure of a tire. Tire air pressure
should be measured when the tire is
cold, or before the vehicle is driven.
(After driving, tire air pressure
increases by about 10%.)As the tire air pressure varies
depending on the vehicle model and
tire size, refer to the VIN and weight
rating plate for the 3.0L diesel
engine, the
“VIN, Weight Rating,
and Greenhouse Gas (GHG)
Emissions Plate,” for the 5.2L diesel
engine, or the “Vehicle Certification
and Greenhouse Gas (GHG)
Emissions Plate” for gas engines on
the driver's door opening frame or
the tire air pressure information on
the following table.

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
318 Vehicle Care
Using worn-out tires is dangerous
because they might have an
increased chance of getting
punctured or bursting while driving.
Check all tires to see if tread wear
indicators appear on their treads
and also check their entire tread for
its depth with a depth gauge to
make sure that the grooves are
deeper than the specified depth.
A tire with tread wear indicators
appearing must be changed. Also,
check the tires for uneven or
otherwise abnormal wear.
{Warning
Tires with excessively shallow
tread grooves will increase the
chance of skidding and, when
driving at high speeds,
hydroplaning. You and others
could be seriously injured.
Hydroplaning occurs when a vehicle
is running at high speeds on a wet
road and a layer of water forms
between the road surface and tires
causing the tires to float on it.
Hydroplaning prevents the driver from steering correctly and from
slowing down the vehicle with the
brake pedal.
Use of Low Aspect Ratio Tires
1. Standard tire
2. Low aspect ratio tire
Low aspect ratio tires for truck
applications (aspect ratio at 70%)
have an air volume 20% to 30%
smaller than that of standard tires.
When air begins to leak, therefore,
low aspect ratio tires adversely
affect vehicle operation much faster
than standard tires. Check air
pressure of low aspect ratio tires
more often than standard tires using
a tire air pressure gauge.
Damaged Tires
{Warning
It is dangerous to mount the
wrong size tire on a wheel. If you
do so, the tire/wheel can explode
as air is being added. This
explosion may result in severe
personal injury or death. For the
3.0L diesel engine, to learn which
wheels and tires are correct, look
at the "VIN and Weight Rating
Plate" on the left side rear pillar
panel below the striker. For the
5.2L diesel engine, to learn which
wheels and tires are correct, look
at the "VIN, Weight Rating, and
Greenhouse Gas (GHG)
Emissions Plate" on the left side
rear pillar panel below the striker
(single cab) or on the left center
pillar panel beside the shoulder
seat belt anchor (crew cab).For
(Continued)

Chevrolet Low Cab Forward Owner Manual (GMNA-Localizing-U.S.-
10716700) - 2017 - crc - 12/6/16
Vehicle Care 319
Warning (Continued)
gas engines, to learn which
wheels and tires are correct, look
at the "Vehicle Certification and
Greenhouse Gas (GHG)
Emissions Plate" on the left side
rear pillar panel below the striker
(single cab) or on the left center
pillar panel beside the shoulder
seat belt anchor (crew cab).
Wheel size is also stamped on
the side of each wheel.
To help avoid personal injury and
property damage if a wheel must
be changed, seek expert tire
services if you can. If you must
remove the wheel without any
such help, do the following:. If the tire looks as if it may
be underinflated, stand to
the side and check whether
the wheel assembly
appears normal by
comparing it to another
wheel assembly on the
vehicle.
(Continued)
Warning (Continued)
.Let the air out of the tire by
taking out the valve core.
If you have a way to put air
back in a tire, note that it is
good safety practice to let
the air out of both tires of a
dual assembly before taking
off the damaged tire and rim
assembly from the vehicle.
After letting out the air, take
off the tire and rim assembly
and install a spare tire and
rim assembly.
If your vehicle is equipped
with a differential lock
system or limited slip
differential (LSD), it might
start moving when the
engine power is transmitted
to the rear axle even when
one of the wheels on the
axle is raised clear of the
ground. Do not start the
engine with any rear wheel
in contact with the ground.
(Continued)
Warning (Continued)
If you are not fully
experienced on the
procedures to follow, and/or
are not equipped with the
proper tools and equipment,
again, do not attempt to
raise the vehicle, or remove
or install the tire and wheel
assembly—seek expert tire
services.
. Do not put air back in a tire
that has been run flat, or is
seriously low on air, without
first having the tire taken off
the wheel and the tire
checked for damage.
. Note that taking off and
mounting tires on wheels
requires proper tools, safety
equipment and special
training. A person can be
severely injured or killed
and damage can result from
using the wrong service
methods. Truck tires and
(Continued)