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
332 Service and Maintenance
.Mounting condition of all
wheel nuts
6. Checks performed after the engine startup
.Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Inspect the exhaust system,
checking that the tailpipe is
clear
7. Checks performed while driving the vehicle
.Brake effectiveness
. Engine abnormal noises
Keep the Floor Around the Driver
Seat Clean and Tidy
{Warning
It is extremely dangerous to have
empty cans, empty bottles,
or other items rolling around on
the floor because they could get
trapped under the brake pedal
and prevent brake application. (Continued)
Warning (Continued)
For proper pedal operation, it is
also essential to lay floor mats
properly. Incorrectly installed floor
mats would hinder free movement
of the pedals.
Do not use the dashboard pocket
or the top of the dashboard as a
place to put items that could roll,
which could interfere with your
driving. You and others could be
seriously injured.
Choose Your Footwear Suitable
for Driving
{Warning
Choose footwear that ensures
proper operation of pedals when
driving the vehicle. Use of
footwear unsuitable for driving
may cause an accident. The
driver could be seriously injured
when not wearing the proper
footwear.
Electrical System
Following the after-delivery service,
it is the owner's responsibility to
check all wiring periodically for
cracked, chafed or oil-soaked
insulation and maintain it in a clean
and tight condition to ensure
satisfactory operation of the
electrical system.
Headlights and Turn Signal
Lights
Turn the engine control switch to the
"ON" position, and then check the
way in which the headlights, turn
signal lights, and other exterior
lights come on and flash. In
addition, press the brake pedal to
confirm whether the stop lights
come on, and shift the transmission
to "R" position to confirm whether
the back up lights come on. Also
examine the lights for discoloration,
damage, and looseness.

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
336 Service and Maintenance
Additional
Maintenance and Care
Owner Safety and Routine
Maintenance
Listed below are vehicle checks
which should be made periodically
by either the owner or a qualified
technician to ensure proper
performance and safety of your
vehicle. Take any problems promptly
to a technician for service advice.
For your safety and that of others,
any of the safety-related
components that may have been
damaged in a crash should be
checked and necessary repairs
performed before operating your
vehicle.
At the minimum, these routine
checks should be made every
6 months or 16,000 km
(10,000 miles), whichever comes
first. Whenever repairs are
necessary, have them completed
before operating the vehicle.A: Parking Brake :
Park on a fairly
steep hill and hold the vehicle with
the parking brake only. This checks
holding ability.
Before checking item (B) below, be
sure to have enough room around
the vehicle. Then firmly apply both
the parking brake see Parking
Brake 0211 and the regular brakes.
Do not use the accelerator pedal.
If the engine starts, be ready to turn
off the engine control switch at
once. Take these precautions
because the vehicle could move
without warning and possibly cause
injury or property damage.
B: Starter Safety Switch : Check
by trying to start the engine in each
gear. The starter should crank only
at selector position "P" or "N".
C: Transmission Shift Indicator :
Check that the indicator points to
the gear chosen.
D: Steering : Be alert for any
changes in steering action. An
inspection or service is needed
when: the steering wheel is harder to turn or has too much free play,
or when there are strange sounds
when turning or parking.
E: Wheel Alignment, Balance, and
Tires :
Check tires for abnormal
wear or damage. Also, check for
damaged wheels. A pull right or left
on a straight and level road may
show the need for a wheel
alignment. A vibration of the
steering wheel or seat at normal
highway speeds may mean a wheel
balancing is needed. Check tire
pressure when the tires are "cold,"
at least monthly, and whenever the
vehicle is serviced.
Check the pressure more often if
daily checks show it's needed.
(Refer to "Recommended Daily
(Pre-operation) Inspections" under
Owner Checks and Services 0330).
Change tire pressure as needed
when changing loads.
F: Brakes : Be alert to illumination
of the brake system warning light or
brake low vacuum warning light
(4500HD, 4500XD models) or the
tone alarm, or changes in braking
action, such as repeated pulling to

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
Service and Maintenance 337
one side, unusual sounds when
braking, increased brake pedal
travel or harder pedal. The front and
rear brakes are attached to an auto
adjuster mechanism. If there are no
defects, as the pedal travel is
properly maintained, adjustments
are not necessary. Check regularly
that the brake fluid reservoir
(left-hand side of the instrument
panel) or HBB reservoir (5500HD,
5500XD models: left side behind the
cab) is properly filled and check for
fluid leaks. Any of these conditions
could indicate the need for brake
system inspection and/or service.
G: Exhaust System :Be alert for
any changes in the sound of the
exhaust system or any smell of
fumes. These are signs the system
may be leaking. Have it checked
and/or repaired at once. (Refer to
"Engine Exhaust Emissions Caution
(Carbon Monoxide)" under Engine
Exhaust 0168).
H: Windshield Wipers and
Washers : Check operation and
condition of the wiper blades. Check
the flow of the washer spray. I: Defroster :
Turn the outlet
selector knob to "Defroster" and the
fan speed control knob to the fully
clockwise position. Then check the
airflow from the ducts at the inside
base of the windshield.
J: Rearview Mirrors and Sun
Visors : Check that friction joints
hold mirrors and sun visors in place.
K: Horn : Sound the horn, now and
then, to be sure it works.
L: Lap-Shoulder Belts : Check the
seat belt system (including webbing,
buckles, latch plates and anchors)
for proper operation, and for
damage.
M: Seat Adjusters : When
adjusting the driver's manual seat,
be sure the seat adjusters latch by
pushing the seat forward and
backward. Do not attempt to adjust
the seat when the vehicle is in
motion.
N: Lamps : Check panel lighting,
warning lamps, indicator lamps and
interior lamps. On the outside,
check: license plate lamps, side
marker lamps, reflectors on outside mirrors, headlamps, parking lamps,
identification and clearance lamps,
taillights, brake lamps, turn signals,
cornering lamps, backup lamps and
hazard warning flashers. Have
headlamp aim checked immediately
if beams seem improperly aimed.
O: Glass, Mirrors, Lights and/or
Reflectors Condition :
Look for
broken, scratched, dirty or damaged
glass, mirrors, lamps or reflectors
that could reduce the view or
visibility, or cause injury. Replace,
clean or repair promptly.
P: Door Latches : Check that doors
close, latch and lock tightly. Check
for broken, damaged or missing
parts that might prevent tight
latching.
Q :Tilt Cab (Driving Position) : Be
sure the tilt lever is down and
locked.
R: Fluid Leaks : Check for fuel,
water, oil or other fluid leaks by
looking at the surface beneath the
vehicle after it has been parked for

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
338 Service and Maintenance
a while. If you notice diesel fumes or
fluid at any time, have the cause
found and corrected at once.
S: Underbody :Corrosive materials
used for ice removal, snow removal
and dust control can collect on the
underbody. If these materials are
not removed, accelerated corrosion
(rust) can occur on underbody parts
such as fuel lines, frame, floor pan
and exhaust system. At least every
spring, flush these materials from
the underbody with plain water.
Take care to clean well any areas
where mud and other debris can
collect. Sediment packed in closed
areas of the frame should be
loosened before being flushed.Checking Components that
Showed Abnormalities during
Previous Operation
Check the components that showed
abnormalities during the previous
operation. Have any abnormalities
repaired by your dealer before using
the vehicle.

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
Technical Data 345
J A L C 4 W 1 6 * L 7 K 0 0 0 0 11 2 3 4 5 6 7 8 9 10 11
Section Description
1 World Manufacturer Identifier (WMI) JAL: ISUZU
2 GVWR and Brake System C: 14,001-16,000 lbs. hydraulic brake system
E: 16,001-19,500 lbs. hydraulic brake system
3 Series Code 4: 4500HD/4500XD
5: 5500HD/5500XD
4 Cab Type Code W: Steel tilt single cab, 71 inch bumper to back of cab (BBC)
J: Non-tilt crew cab, 110 inch bumper to back of cab (BBC)
5 Chassis Type Code 1: 4 x 2
6 Engine Code 6: 4HK1
7 Check Digit
8 Model Year Code L: 2020

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
354 Technical Data
Parking Brake
Lever effective stroke (Under pull force of approx. 147 N (15 kg/33 lb) 6–8 notches
Electrical System
Battery type [BCI size] (RC-CCA) x No. of units 31T (160–950) x 2
*7
Starter
12 V/3.0 kw
Alternator 12 V/140 amp
Tightening Torque
Oil pan drain plug 83.3Y(8.5 kgf m/61.0 lb ft)
Oil filter drain plug —
Oil filter —
Oil filter cartridge 63.7Y(6.5 kgf m/47.0 lb ft)
Remarks:
*1see Engine Oil 0235.
Remarks:*2see Engine Coolant 0243.
Remarks:*3see Automatic Transmission Fluid 0241.
Remarks:*4see Rear Axle (Gear Oil Viscosity Chart) 0261 or
Rear Axle (Oil Level Check) 0262.
Remarks:
*5only for vehicles equipped with optional limited slip differential.
Remarks:*6The fuel tank capacity is stated on a metal plate attached to the fuel tank body. Only fill the tank to
95 percent of its capacity; this allows room for the expansion of the fuel.
Remarks:
*7larger capacity batteries 31 (180-930) × 2 can also be used. However, do not mix batteries of different
types and from different makers.

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
Technical Data 355
Engine Drive Belt Routing
Fan Belt and Air Conditioning
Compressor Belt
See theMaintenance Schedule
0 317.
No. Name
1 Fan belt
2 Fan pulley
3 A/C belt
4 A/C compressor
5 Tension pulley
6 Crank pulley No.
Name
7 Alternator
If your air conditioning system is
functioning properly, it is not
necessary to remove and replace
the refrigerant or compressor oil.
. A V-ribbed belt is used for the
fan belt. This type of belt
requires the tension to be
adjusted more accurately than is
required with the conventional V
belt. Inappropriate tension could
cause the belt to make noise or
break. When the fan belt is
damaged, electricity is not
properly generated or becomes
a cause of engine overheating.
You must check the tension of
the fan belt carefully.
. Use dealer-certified genuine
parts when changing the
fan belt.
. Have the vehicle inspected and
serviced at your dealer. .
The air conditioning drive belt,
if equipped, must be adjusted
after fan belt adjustment. If the
belt is not adjusted properly, the
A/C belt may experience
excessive tension, and possible
premature failure.

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
362 Customer Information
Publication Ordering
Information
Service Manuals
Service manuals have the diagnosis
and repair information on the
engine, transmission, axle,
suspension, brakes, electrical
system, steering system, body, etc.
Customer Literature
Owner’s manuals are written
specifically for owners and are
intended to provide basic
operational information about the
vehicle. The owner ’s manual
includes the Maintenance Schedule
for all models.
Customer literature publications
available for purchase include
owner ’s manuals, warranty
manuals, infotainment manuals, and
portfolios. Portfolios include an
owner ’s manual, warranty manual,
infotainment manual, if applicable,
and zip lock bag or pouch.
Current and Past Models
Service manuals and customer
literature are available for many
current and past model year GM
vehicles.
To order, call 1-800-551-4123
Monday–Friday, 8:00 a.m.–6:00 p.m.
eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see
Helm, Inc. at: www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.
Radio Frequency
Statement
This vehicle has systems that
operate on a radio frequency that
complies with Part 15 of the Federal
Communications Commission (FCC)
rules. Operation is subject to the following
two conditions:
1. The device may not cause harmful interference.
2. The device must accept any interference received, including
interference that may cause
undesired operation of the
device.
Changes or modifications to any of
these systems by other than an
authorized service facility could void
authorization to use this equipment.