Electrical ISUZU KB P190 2007 Workshop Manual PDF

Engine Control System (4JH1) 6E-283
Description And Operation
Engine Control Module (ECM) Description



RTW 66ESH001201
The engine control module (ECM) is designed to
withstand normal current draws associated with vehicle
operation. Avoid overloading any circuit. W hen testing
for opens and shorts, do not ground or apply voltage to
any of the ECM circuits unless instructed to do so. In
some cases, these circuits should only be tested using
a digital multi meter (DMM). The ECM should remain
connected to the ECM harness.
The ECM is located on the floor panel. The ECM mainl
y
controls the following.
• The fuel system control
• The exhaust gas recirculation (EGR) system
control
• The preheating (glow) system control
• The A/C compressor control
• On-board diagnostics for engine control
The ECM constantly observes the information from
various sensor s. The ECM controls the systems that
affect vehicle performance. The ECM performs the
diagnostic function of the system. The ECM can
recognize operational problems, alert the driver through
the malfunction indicator lamp (MIL), and store
diagnostic trouble codes (DTCs). DTCs identify the
system faults to aid the technician in making repairs.





ECM Voltage Description
The ECM supplies a buffered voltage to various
switches and sensor s. The ECM can do this because
resistance in the ECM is so high in value that a test
lamp may not illuminate when connected to the circuit.
An ordinary shop voltmeter may not give an accurate
reading because the voltmeter input impedance is too
low. Use a 10-megaohm input impedance DMM, to
ensure accurate voltage readings. The input and/o
r
output devices in the ECM include analog-to-digital
converters, signal buffers, counters, and special drivers.
The ECM controls most components with electronic
switches which complete a ground circuit when turned
ON.
Aftermarket Electrical and Vacuum Equipment
Aftermarket or add-on electrical and vacuum equipment
is defined as any equipment which connects to the
vehicle's electrical or vacuum systems that is installed
on a vehicle after the vehicle leaves the factory. No
allowances have been made in the vehicle design fo
r
this type of equipment. No add-on vacuum equipment
should be added to this vehicle. Add-on electrical
equipment must only be connected to the vehicle's
electrical system at the battery power and ground. Add-
on electrical equipment, even when installed to these
guidelines, may still cause the powertrain system to
malfunction. This may also include equipment not
connected to the vehicle electrical system such as
portable telephones and audios. Therefore, the first
step in diagnosing any powertrain fault is to eliminate all
aftermarket electrical equipment from the vehicle. Afte
r
this is done, if the fault still exists, the fault may be
diagnosed in the normal manner.
Electrostatic Discharge Damage
Electronic components used in the ECM are often
designed to carry very low voltage. Electronic
components are susceptible to damage caused b
y
electrostatic discharge. By comparison, as much as
4,000 volts may be needed for a person to feel even the
zap of a static discharge. There are several ways for a
person to become statically charged. The most
common methods of charging are by friction and
induction. •
An example of charging by friction is a person
sliding across a vehicle seat.


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ISUZU KB P190 2007

PAGE
Section 6A Engine Mechanical .................................................................................... 1361
Section 6B Engine Cooling .......................................................................................... 1524
Section 6C Fuel System ............................................................................................... 1542
Section 6D Engine Electrical ....................................................................................... 1589
Section 6E Engine Control System ............................................................................ 1618
Section 6F Exhaust System ........................................................................................ 1986
Section 6H Engine Speed Control System ................................................................ 1998
SECTION 6
ENGINE
TA BLE OF CONTENTS
ENGINE 6
4JK
1/4J J1 MODELS

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ENGINE MECHANICAL (4JK1/4JJ1) 6A-3
ISUZU DIESEL ENGINE (4JK1/4JJ1)
Service Precautions
Matters that require attention in terms of
maintenance
To prevent damage to the engine and ensure reliabilit
y
of its performance, pay attention to the following in
maintaining the engine:
• W hen lifting up or supporting the engine, do not
apply a jack on the oil pan.
W hen taking down the engine on the ground, do not make the bearing surface of the oil pan touch
the ground directly. Use a wooden frame, fo
r
example, to support the engine with the engine
foot and the flywheel housing.
Because there is only a small clearance between the oil pan and the oil pump strainer, it can
damage the oil pan and the oil strainer.
• W hen the air duct or air cleaner is removed, cove
r
the air intake opening to prevent foreign matter
from getting into the cylinder. If it gets
contaminated, it can considerably damage the
cylinder and others while the engine is operating.
• W hen maintaining the engine, never fail to remove
the battery earth cable. If not, it may damage the
wire harness or electrical parts. If you need
electricity on for the purpose of inspection, fo
r
instance, watch out for short circuits and others.
•
Apply engine oil to the sliding contact surfaces of
the engine before reassembling it. This ensures
adequate lubrication when the engine is first
started.
• W hen valve train parts, pistons, piston rings,
connecting rods, connecting rod bearings o
r
crankshaft journal bearings are removed, put them
in order and keep them.
• W hen installing them, put them back in the same
location they were removed from.
• Gaskets, oil seals, O-rings, etc. must be replaced
with new ones when the engine is reassembled.
•
As for parts where a liquid gasket is used, remove
an old liquid gasket completely and clean it up
thoroughly so that no oil, water or dust is clinging
to them. Then, apply the designated liquid gasket
to each place anew before assembly.

• Surfaces covered with liquid gasket must be
assembled within 5 minutes of gasket application.
If more than 5 minutes has elapsed, remove the
existing liquid gasket and apply a new liquid
gasket.
• W hen assembling or installing parts, fasten them
with the prescribed tightening torque so that the
y
are installed properly.

Matters that require attention in specifically dealing
with this engine.
Holes or clearances in the fuel system, which serve as
a passage of fuel, including the inside of the injector,
are made with extreme precision. For this reason, the
y
are highly sensitive to foreign matter and, if it gets in, it
can lead to an accident on the road, for instance; thus,
make sure that foreign matter is prevented from getting
in.

W hen servicing the fuel system, every precaution must
be taken to prevent the entry of foreign material into the
system.
• Before beginning the service procedure, wash the
fuel line and the surrounding area.
• Perform the service procedures with clean hands.
Do not wear work gloves.
• Immediately after removing the fuel hose and/o
r
fuel pipe, carefully tape vinyl bags over the
exposed ends of the hose or pipe.
• If parts are to be replaced (fuel hose, fuel pipe,
etc.) do not open the new part packaging until
installation.

Work procedure
• The fuel opening must be quickly sealed when
removing the fuel pipe, injection pipe, fuel injector,
fuel supply pump, and fuel rail.
• The eyebolts and gasket must be stored in a clean
parts box with a lid to prevent adhesion of foreign
matter.
• Fuel leakage could cause fires. Therefore, afte
r
finishing the work, wipe off the fuel that has leaked
out and make sure there is no fuel leakage afte
r
starting the engine.


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6A-8 ENGINE MECHANICAL (4JK1/4JJ1)
Trouble Shooting
Engine does not turn over
Condition Possible Cause Correction
Dead or weak battery Charge battery
Replace battery
Incomplete circuit Connect
Repair
Starter motor brushes stuck, worn,
or broken Replace brushes
Starter motor does not rotate
Starter motor internal damage Repair motor
Ring gear abrasion Replace ring gear Starter motor not meshed with
flywheel Magnetic switch (starter motor) not
properly adjusted Adjust
Dead or weak battery
Charge battery
Replace battery
Insufficient contact pressure
between starter motor brushes and
commutator Adjust pressure
Armature (starter motor) stuck Repair armature
Starter motor pinion meshed with
ring gear but does not rotate
Engine internal damage (Seizure) Repair engine

Engine turns over but does not start
Condition Possible Cause Correction
Air in fuel system Bleed air from fuel system
Air entering fuel pipe Replace pipe and bleed air from
fuel system
Empty fuel tank Replenish fuel
Clogged strainer (fuel suction) Clean or replace strainer
Clogged fuel pipe Clean or replace pipe
Feed pump malfunction Replace pump
Use of wrong fuel for prevailing
temperatures Drain existing fuel and replace with
appropriate fuel
Fuel is not delivered to fuel supply
pump
Clogged fuel filter Replace filter
Loose injection pipe connections Tighten connections
Loose or broken electrical
connectors Tighten and/or replace connectors
Bad rotational sensor
Replace sensor
Fuel is delivered to fuel supply
pump
Engine control system malfunction System diagnosis
Air in fuel system Bleed air from fuel system
Feed pump malfunction Repair pump
Loose or broken electrical
connectors Tighten and/or replace connectors
Clogged fuel filter
Replace filter
Insufficient or unstable fuel delivery
volume
Engine control system malfunction System diagnosis

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6C-22 FUEL SYSTEM (4JK1/4JJ1)
Removal
1. Remove the starter motor.
• Refer to the removal procedure for engine
electricals in this manual.
2. Remove the fuel feed pipe (1) for supply pump.
Note: Cover the areas exposed during parts removal to
prevent the entry of foreign material into the fuel
system.



RTW 76CSH000501
3. Remove the fuel hose (1).
Note: Cover the areas exposed during parts removal to
prevent the entry of foreign material into the fuel
system.





RTW 76CSH000601

4. Remove the leak off pipe and hose (1).
Note: Cover the areas exposed during parts removal to
prevent the entry of foreign material into the fuel
system.




RTW 76CSH000301
5. Disconnect the fuel rail pressure sensor harness
connector (1).




LNW 76CSH001601


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FUEL SYSTEM (4JK1/4JJ1) 6C-25
6. Tighten the fuel leak off pipe and hose (1) using
the mounting eyebolt using the specified torque.
Tightening torque: 10 N ⋅
⋅⋅
⋅
m (1.0 kg ⋅
⋅⋅
⋅
m/87 lb in)




RTW 76CSH000401
7. Install the fuel hose (1).





RTW 76CSH000601

8. Install the fuel feed pipe (1) for supply pump and
tighten the bolts to the specified torque.
Tightening torque: 44 N ⋅
⋅⋅
⋅
m (4.5 kg ⋅
⋅⋅
⋅
m/33 lb ft)



RTW 76CSH000501
9. Install the starter motor. • Refer to removal procedure for engine
electricals in this manual.



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6C-44 FUEL SYSTEM (4JK1/4JJ1)
Fuel Tube / Quick - Connector Fittings
Precautions
• Do not light a match or create a flame.
• Keep flames away from your work area to prevent
flammable materials from catching fire.
• Disconnect the battery ground cable to prevent
electrical shorts.
• Pre −treat the piping system or associated parts
from thermal damage or from spattering when
welding or similar heat −generating work.

Cautions During Work
Do not expose the assembly to battery electrolyte or do
not wipe the assembly with a cloth used to wipe off spilt
battery electrolyte.
Piping that has been splattered with battery electrolyte
or battery electrolyte soaked cloth that was wiped on the
piping cannot be used.






140R100032
Legend
1. O-ring
2. Port
3. Connector
4. Plastic Tube


Removal
1. Open the fuel cap to relieve the fuel pressure in
the tank. Use compressed air to remove any dirt
on the fuel quick connect fittings prior to
disconnecting the fittings. W hen disconnecting the
fuel pipe, cover the area with a cloth to prevent
fuel from splashing as the fuel pipe may still have
some pressure in it.





140R100002
2. For removal of the quick connector, hold the quick
connector in one hand, and pull out the connecto
r
with the other hand while pressing the square
release button of the connector, as illustrated.


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ENGINE ELECTRICAL (4JK1/4JJ1) 6D-1
SECTION 6D
ENGINE ELECTRICAL
TABLE OF CONTENTS

Charging System ................................................ 6D-2
Servicing Cautions .......................................... 6D-2
Important Generator Components and
Function.......................................................... 6D-2
Troubleshooting .............................................. 6D-5
Diagnosis......................................................... 6D-7
Specifications .................................................. 6D-8
Unit Se rv ic ing (4 JJ 1) ....................................... .... ..6D -9
Disassembly .................................................... 6D-10
Inspection and Repair ..................................... 6D-11 Rotor Assembly ........................................... 6D-11
Stator Coil .................................................... 6D-12
Brushes ....................................................... 6D-12
Rectifier ....................................................... 6D-13
Regulator Assembly..................................... 6D-13
Measuring Procedure .................................. 6D-13
Reassembly..................................................... 6D-14
Final Assembly ................................................ 6D-14
Starter Motor ...................................................... 6D-15 Starting Circuit Diagram .................................. 6D-15
Removal and Installation ................................. 6D-15 Important Operations – Removal................. 6D-15
Important Operations – Installation.............. 6D-15
Disassembly .................................................... 6D-16 Disassembly Steps ...................................... 6D-16
Important Operations ................................... 6D-17
Inspection and Repair ..................................... 6D-20 Armature ...................................................... 6D-20
Yoke............................................................. 6D-21
Brush and Brush Holder .............................. 6D-22
Overrunning Clutch...................................... 6D-22
Bearing ........................................................ 6D-23
Reassembly..................................................... 6D-24 Reassembly Steps ....................................... 6D-24
Important Operations ................................... 6D-25
Inspection After Assembly ........................... 6D-26
Magnetic Switch .............................................. 6D-27
Torque Specifications...................................... 6D-28

Pre-Heating System ........................................... 6D-29 Inspection and Repair ..................................... 6D-29 Visual Check................................................ 6D-29
Glow Relay .................................................. 6D-29
Glow Plug .................................................... 6D-29


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6D-2 ENGINE ELECTRICAL (4JK1/4JJ1)
Charging System
Servicing Cautions
• Battery polarity is important. If the battery cables
are reversed, the generator diodes will be
destroyed.
• Do not remove the battery cables or the charging
circuit wiring when the engine is running.
• Confirm that the terminal wires are connected to
the proper terminals by checking the terminal
numbers (the number on the terminal wire and the
terminal must be the same).
• Disconnect the battery negative cable (-) before
inspecting the generator.
• Do not open or close the battery relay switch when
the engine is running.
• Disconnect the battery negative cable (-) when
using external equipment (Quick-Charge) to
charge the battery.
• W hen steam cleaning or washing the engine, do
not allow steam or water to come in direct contact
with the battery and other electrical system
components.
• Be sure to read the item on belt tension
adjustment before beginning the procedure.
Important Generator Components
and Function
• The generator used on 4JK1 engine cannot be
disassembled.
• The generator uses a built-in solid-state IC voltage
regulator. The regulator and other important
components together with their connections are
shown in the illustration.
• The voltage regulator is installed to the rear cove
r
assembly of the generator together with the brush
holder and the rectifier. The generator requires no
additional voltage regulation.
• 9 diodes are connected to the stator coil to convert
AC to DC. The DC voltage is delivered to the
generator output terminal.


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ENGINE ELECTRICAL (4JK1/4JJ1) 6D-3
AC Generator (4JK1)



RTW 56DMF000501
AC Generator (4JJ1)



RTW 76DMF000101

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