check engine CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

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
328 Service and Maintenance
21. Brake Fluid :Check the fluid in
the brake fluid reservoir every
16 000 km (10,000 miles). Replace
the fluid every 48 000 km
(30,000 miles).
22. Hydraulic Brake Booster Fluid
(5500HD, 5500XD models) :
Replace Dexron VI ATF fluid every
24 months or 30,000 miles
(48,000 km), whichever occurs first.
23. Brake Line and Hoses : Check
lines and hoses for proper hook-up,
binding, leaks, cracks, chafing, etc.
every 32 000 km (20,000 miles).
Any questionable parts should be
replaced or repaired at once. When
rubbing or wear is noted on lines or
hoses, the cause must be corrected
at once.
24. Parking Brake Cable : Check
the parking brake cable every
16 000 km (10,000 miles) or
12 months whichever occurs first.
25. Automatic Transmission
Fluid : Check the automatic
transmission fluid level at each engine oil change and replace fluid
every 48 000 km (30,000 miles). Do
not overfill.
26. Differential Gear Oil :
Replace
lubricant every 48 000 km
(30,000 miles). Check lubricant level
every 16,000 km (10,000 miles) or
every 12 months, and add lubricant
to within 0 to 10 mm (0 to 0.4 inch)
of the bottom edge of the filler hole
if necessary.
27. Power Steering Fluid :
Replace power steering fluid every
24 months or 48 000 km
(30,000 miles), whichever occurs
first.
28. Power Steering Oil Hoses :
Replace power steering oil hoses
every 24 months or 80 000 km
(50,000 miles), whichever occurs
first.
29. Steering Wheel Free Play :
Check steering wheel free play after
the first 1 040 km (650 miles) and
then every 10 400 km (6,500 miles).
Steering wheel free play
10-50 mm (0.39-1.97 in) 30. Steering Gear Box Torque :
Retighten the attaching bolts of the
steering gear box to the specified
torque every 12 months or every
32 000 km (20,000 miles) whichever
occurs first.
Steering gear box tightening torque
103 Y(76 lb·ft)
31. Driveshaft Flange Torque :
Check the fixing bolts of driveshaft
flange for looseness or damage
after the first 16 000 km
(10,000 miles). Driveshaft flange tightening torque
103Y(76 lb·ft)
32. Driveshaft Lubrication :
Lubricate the grease fitting on the
center bearing, as well as each
universal joint and spline coupling
every 12 months or 16 000 km
(10,000 miles) whichever occurs
first.

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 329
33. Leaf Spring U-bolt Torque :
Tighten the U-Bolt nuts to the
specified torque after the first
1 040 km (650 miles), thereafter
every 16 000 km (10,000 miles).Model Leaf spring U-bolt nut tightening torque
Front Rear
4500HD 127 Y
(94 lb·ft) 177
Y
(131 lb·ft)
4500XD 196 Y
(145lb·ft) 177
Y
(131 lb·ft)
5500HD, 5500XD 196
Y
(145lb·ft) 284
Y
(209 lb·ft)
34. Wheel Nut Torque : Check tires
for excessive or abnormal wear,
or damage. Also check tire inflation
pressures and adjust.
Be sure wheels are not bent or
cracked and that wheel nuts have
been tightened to the specified
torque after the first 1,040 km
(650 miles) and then every
10 400 km (6,500 miles). Note that
there are left and right hand
threads. Wheel nut tightening torque
500Y(362 lb·ft)
35. King Pin : Lubricate the grease
fitting on the king pins every
12 months or 16 000 km
(10,000 miles) whichever occurs
first.
36. Wheel Hub Bearing Grease :
Clean and repack front wheel
bearings every 24 months or
48 000 km (30,000 miles) whichever
occurs first.
37. Air Conditioner Blower
Filter : The air conditioner blower
filter should be removed and
cleaned once a month.
38. Exhaust Injector : Clean the
exhaust injector every 176,000 km
(110,000 miles).
39. DEF Supply Pump Filter
Element : Replace the DEF supply
pump filter element every
192 000 km (120,000 miles) or
24 months whichever occurs first. 40. Starter :
The color displayed by
the starter indicator light will change
from green to amber when the
number of times remaining is 0 or
below and the screen is selected.
When the indicator light (amber)
comes on, have the vehicle
inspected/serviced at the nearest
dealer.
41. Wiper Blades : Inspect wiper
blades for wear, cracking,
or contamination. Clean the
windshield and wiper blades,
if contaminated, replace wiper
blades that are worn or damaged,
or at least once a year. See Wiper
Blade Replacement 0265.

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
330 Service and Maintenance
Owner Checks and
Services
Before Driving
Proper care and driving is important
not only for extended service life of
your vehicle, but also for improved
fuel and oil economy. Drive carefully
and defensively. Be sure you know
how to use your truck and its
equipment before operating it.
Starting and Operating
Proper care and operation will not
only extend the service life of your
vehicle but also improve fuel
economy.
Check Around the Vehicle Before
Starting the Engine
Before pulling away, perform a
thorough safety check, making sure
there are no children or obstructions
around the vehicle.
Take off the chocks after confirming
that the parking brake is securely
applied. Sit behind the wheel, adjust
the seat position, and buckle up theseat belt. The passengers are also
required to buckle up the seat belts.
Adjust the positions of the steering
wheel and mirrors. Lock the doors.
Turn the power of the dome light or
accessories OFF before starting the
engine.
Engine Conditions
Checking the Engine for
Startability and Abnormal Noises
1. Make sure the parking brake is securely engaged. Step firmly
on the brake pedal.
2. Make sure the selector lever is in "P" or "N" position.
For safety, firmly press the
brake pedal before starting the
engine.
3. Turn the engine control switch to start the engine.
Check that the engine starts
quickly with no abnormal
noises. Checking Condition of the Engine
at Low Speeds and during
Acceleration
1. Make sure the transmission is in the "P" or "N" position and
the parking brake is securely
engaged.
2. Turn the engine control switch to start the engine, and run it to
warm up.
3. Check that the engine is running at a speed within the
standard idle speed range.
During regeneration of the
diesel particulate filter (DPF),
the engine idle speed may
increase.
4. Drive the vehicle, making sure the accelerator pedal does not
stick when gradually
accelerating, the engine speed
rises smoothly and it does not
knock.

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 331
Recommended Daily
(Pre-operation) Inspections
These checks are in addition to, not
instead of, any legally required daily
inspections. See related topics
under "Maintenance Schedule",
especially if problems are found.
For safe and comfortable driving,
keep record of the distances driven
and the condition of the vehicle
during operation. Perform
inspections at appropriate intervals,
and perform maintenance in
accordance with the findings of the
inspections. If an inspection reveals
an abnormality or there was an
abnormality the previous time the
vehicle was driven, have the vehicle
repaired by the nearest dealer
before it is driven again.1. Components that showed abnormalities during the
previous operation
.Check components that
showed abnormalities
during the previous
operation 2. Checks performed at the
engine
.Fan belt looseness and
damage
. Engine oil level
. Engine coolant level
. Power steering fluid level
3. Checks performed from the driver's seat
.Brake fluid level
. Brake pedal free play
. Operation of meters,
gauges and warning/
indicator lights
. Engine startability,
abnormal noise and color of
exhaust gases
. Parking brake lever stroke
. Windshield washer fluid
spray condition and
windshield wiper
effectiveness
. Windshield washer fluid
level .
Steering wheel position and
free play
. Operation of horn and turn
signal lights
. Door lock operation
4. Checks performed during a walk around the vehicle
.Illumination, flashing,
contamination, damage and
obstruction of lights
. Contamination, damage ad
obstruction of windows,
mirrors and reflectors
. Leaf spring damage
. Oil, engine coolant, fuel,
brake fluid and power
steering fluid leaks
. Water separator
5. Checking wheels and tires .Air pressure
. Cracks and other damage
. Abnormal wear
. Tread depth

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.