2007 ISUZU KB P190 relay

Engine Control System (4JH1) 6E-255
Symptoms – Engine Controls
Symptoms – Engine Controls
Important Preliminary Inspections Before Starting
Perform Diagnostic System Check – Engine Controls
before using the symptom tables, and verify that all o
f
the following are true:
• The engine control module (ECM) and malfunction
indicator lamp (MIL) are operating correctly.
• There are no diagnostic trouble codes (DTCs)
stored, or a DTC exists but without the MIL.
• The scan tool data is within the normal operating
range. Refer to scan tool Data List in this section.
• Verify the customer concern and locate the correct
symptom in the table of contents. Inspect the items
indicated under that symptom.
Visual and Physical Inspection
Several of the symptom procedures ask for careful
visual and physical inspection. This step is extremel
y
important. The visual and physical inspection can lead
to correcting a problem without further inspections, and
can save valuable time. Ensure that:
• The ECM grounds are clean, tight, and in thei
r
proper location.
• The vacuum hoses are not split or kinked, and
properly connected. Inspect thoroughly for an
y
type of leak or restriction.
• The mass air flow (MAF) sensor is properl
y
installed. The arrows on the plastic portion of the
sensor must point toward the engine.
• The air intake ducts are not collapsed or damaged.
• There are no leaks at the MAF sensor, an
y
connections or intake manifold sealing surfaces.
• The engine harness wiring and terminals are
properly connected and are not pinched or cut.
Intermittent
Important:
Inspect for improper installation of electrical
components if an intermittent condition exists. Inspect
for aftermarket add-on electrical equipment devices,
lights, and cellular phones. Verify that no aftermarket
equipment is connected to the keyword 2000 serial data
circuit. If you cannot locate an intermittent condition, a
cellular phone communication signal may cause the
condition.
Important:
The problem may or may not turn ON the MIL or store a
DTC.

Faulty electrical connections or wiring cause most
intermittent problems. Perform a careful visual and
physical inspection of the suspect connectors for the
following conditions:
• Improperly mated connector halves
• Terminals that are not seated
• Terminals that are damaged or improperly formed
Reform or replace connector terminals in the problem
circuit in order to ensure proper contact tension.
Remove the terminal from the connector body in orde
r
to inspect for poor terminal wire connection.
Road test the vehicle with the DMM connected to the
suspected circuit. An abnormal reading that occurs
when the malfunction occurs is a good indication that
there is a malfunction in the circuit being monitored.
Use the scan tool in order to help detect intermittent
conditions. Useful features of the scan tool include the
following:
• Trigger the Snapshot feature in order to capture
and store engine parameters when the malfunction
occurs. Review this stored information in order to
see the specific running conditions that caused the
malfunction.
• Use the Plot Function on the scan tool in order to
plot selected data parameters. Review this stored
information to aid in locating an intermittent
problem. Refer to the scan tool Users Guide fo
r
more information.
Important:
If the intermittent condition exists as a start and then
stall, test for DTCs relating to the vehicle theft deterrent
system. Test for improper installation of electrical
options such as lights, cellular phones, etc.
Any of the following may cause an intermittent MIL with
no stored DTC:
• The ECM grounds are loose or dirty. Refer to
Engine Controls Schematics.
• The MIL circuit intermittently shorted to ground.
• Electrical system interference caused by a
malfunctioning relay, ECM driven solenoid, o
r
switch. The electrical component can cause a
sharp electrical surge. Normally, the problem will
occur when the malfunctioning component is
operating.
• There is an open diode across the A/C
compressor clutch or any other open diodes.



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ISUZU KB P190 2007

6E-258 Engine Control System (4JH1)
Checks Action
Electromagnetic Interference (EMI)
and Electrical Noise Some electrical components/circuits are sensitive to EMI or other types of electrical
noise. Inspect for the following conditions:
• A misrouted harness that is too close to high voltage/high current devices such as
injection components, motors, generator etc. These components may induce
electrical noise on a circuit that could interfere with normal circuit operation.
• Electrical system interference caused by a malfunctioning relay, or the engine control
module (ECM) driven solenoid or switch. These conditions can cause a sharp
electrical surge. Normally, the problem will occur when the malfunctioning
component is operating.
• Improper installation of non-factory or aftermarket add on accessories such as lights,
2-way radios, amplifiers, electric motors, remote starters, alarm systems, cell
phones, etc. These accessories may lead to an emission related failure while in use,
but do not fail when the accessories are not in use.
• Test for an open diode across the A/C compressor clutch and for other open diodes.
Some relays may contain a clamping diode.
• Test the generator for a bad rectifier bridge that may be allowing AC noise into the
electrical system.
Incorrect ECM Programming • There are only a few situations where reprogramming a ECM is appropriate:
Important:
DO NOT reprogram the ECM with the SAME software/calibration files that are already
present in the ECM. This is not an effective repair for any type of driveability problem. - A ECM from another vehicle is installed.
- Revised software/calibration files have been released for this vehicle.
• Verify that the ECM contains the correct software/calibration. If incorrect
programming is found, reprogram the ECM with the most current
software/calibration.
Duplicating Failure Conditions • If none of the previous tests are successful, attempt to duplicate and/or capture the
failure conditions.
• An alternate method is to drive the vehicle with the DMM connected to a suspected
circuit. An abnormal reading on the DMM when the problem occurs, may help you
locate the problem.
scan tool Snapshot The scan tool can be set up to take a Snapshot of the parameters available via serial
data. The Snapshot function records live data over a period of time. The recorded data
can be played back and analyzed. The scan tool can also graph parameters singly or
in combinations of parameters for comparison. The Snapshot can be triggered
manually at the time the symptom is noticed, or set up in advance to trigger when a
DTC sets.
An abnormal value captured in the recorded data may point to a system or component
that needs to be investigated further.
Refer to the scan tool user instructions for more information on the Snapshot function.


Hard Start
Checks Action
DEFINITION:The engine cranks OK, but does not start for a long time. The engine does eventually run, or may start but
immediately dies.
Preliminary Checks •
Diagnostic System Check - Engine Controls.
• Ensure the driver is using the correct starting procedure.
• Inspect the engine control module (ECM) and fuel injection pump control unit (PCU)
grounds for being clean, tight, and in their proper locations.
• Inspect that the harness connectors are correctly connected.
• Inspect the fuel type and quality.
• Inspect the scan tool Data List in this section.
• Inspect the Service Bulletins for ECM software updates.

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ISUZU KB P190 2007

ENGINE MECHANICAL (4JK1/4JJ1) 6A-5
EGR system
Based upon data, including water temperature, engine
speeds or engine loads, it is controlled via Engine
Control Module (ECM) to purify exhaust by recycling
part of it.
Its main components include an EGR valve, an EGR
cooler and various sensors.

Connecting rod cap bolt
The angular tightening method of the connecting rod
cap bolt further increases reliability and durability.

Fuel rail-type electronic control injection system
The fuel rail-type electronic control injection system is
composed of a fuel supply pump that sets the target
pressure of high-pressure fuel and supply it, a fuel rail
that measures such high-pressure fuel and a fuel
injector that turns it into a fine spray and injects it. Each
is controlled via ECM based upon various signals, while
injection timing or fuel injection quantity is controlled
under every possible driving condition.

Fuel injector
The fuel injector is a 6-hole nozzle that adjusts fuel
injection quantity or injection timing by opening o
r
closing an electromagnetic valve on the head of the fuel
injector.
ECM corrects the dispersion of fuel injection quantit
y
between fuel injector according to ID code data in
memory. At the replacement of fuel injector, ID code
data should be stored in ECM.


Fuel filter with sedimenter
It is a fuel filter with sedimenter that gets rid of water by
making use of the difference in specific gravity between
light oil and water, which comes with an indicator that
notifies you that it is filled with water.

Preheating system
The preheating system consists of the ECM, the glow
relay, glow plugs and the glow indicator lamp. The
preheating system is operated when the engine coolant
temperature is low, and makes the engine easy to start.

Lubrication system
It is an oil filter with full-flow bypass, which uses a
water-cool oil cooler and oil jet to cool the piston.

Functional inspection
Inspection/adjustment of valve clearance 1. Inspection of valve clearance
• Remove the fuel injector harness assembly.
• Remove the leak off hose.
• Remove the cylinder head cover.
• Rotate the crankshaft to make the No.1
cylinder meet the compression top dead cente
r
(TDC).





RTW 76ASH001301
Legend
1. TDC



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ISUZU KB P190 2007

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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ISUZU KB P190 2007

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-29
Pre-Heating System
Inspection and Repair
Make the necessary adjustments, repairs, and part
replacement if excessive wear of damage is discovered
during inspection.
Visual Check
Check the main fuses and glow indicator for damage.
Replace the part(s) if required.
Glow Relay
The glow relay is located in the relay box the engine
compartment.
Use an ohmmeter to measure the resistance between
terminals No.2 and No.3.
If the measured value is outside the specified range, the
glow relay must be replaced.
Glow Relay Resistance Ohms
94 - 114

















825R300046

Glow Plug
Use a circuit tester to test the glow plugs for continuity.
Glow Plug Resistance (Reference) Ohms
Approximately 0.9



LNW 21KSH001401



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6E-6 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
P0501 25 AAA Vehicle Speed Sensor Circuit Range/ Performance
P0512 417 C -- Starter Request Circuit
P0562 35 C AA System Voltage Low
P0563 35 C AA System Voltage High
P0565 515 D D- Cruise Control On Signal
P0566 516 D D- Cruise Control Off Signal
P0567 517 D D- Cruise Control Resume Signal
P0568 518 D D- Cruise Control Set Signal
P0571 26 D D- Brake Switch Circuit
P0601 53 C AA Internal Control Module Memory Check Sum Error
P0602 154 C AA Control Module Programming Error
P0604 153 C AA Internal Control Module RAM Error
P0606 51 C AA ECM Processor
P0615 19 C -- Starter Relay Circuit
P0633 176 C AA Immobilizer Not Programmed
P0638 61 A AA Throttle Actuator Control Range/ Performance
P0642 55 C AA Sensor Reference Voltage 1 Circuit Low
P0643 55 C AA Sensor Reference Voltage 1 Circuit High
P0650 77 A AA Malfunction Indicator Lamp (MIL) Control Circuit
P0652 56 A AA Sensor Reference Voltage 2 Circuit Low
P0653 56 A AA Sensor Reference Voltage 2 Circuit High
P0661 58 C AA Intake Manifold Turning Valve Control Circuit Low
P0662 58 C AA Intake Manifold Turning Valve Control Circuit High
P0698 57 A AA Sensor Reference Voltage 3 Circuit Low
P0699 57 A AA Sensor Reference Voltage 3 Circuit High
P0700 185 A A- Transmission Control System (MIL Request)
P1064 247 A AA Fuel Pressure Regulator Control Circuit
P1065 247 A AA Fuel Pressure Regulator Control Circuit
P1093 227 A AA Fuel Rail Pressure Too Low
P1094 226 A AAFuel Rail Pressure Too Low (FRP Regulator
Commanded High)
P1094 226 C AA Fuel Rail Pressure Too Low (Fuel Pressure Drop)
P1196 461 A AA Intake Throttle Solenoid Control Driver
P1197 461 A AA Intake Throttle Solenoid Control Driver
P1198 461 A AA Intake Throttle Solenoid Control Driver
P124B 157 C AA Injector Circuit Short Across Group 1 & 2
P1261 34 A AA Injector Positive Voltage Control Circuit Group 1
P1261 34 A AAInjector Positive Voltage Control Circuit (Supply Voltage
Low)
DTC
Flash
Code DTC Type
DTC Descriptor
Euro 4
Specification Except Euro 4
Specification
(High Output) Except Euro 4
Specification (Standard Output)

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6E-10 ENGINE CONTROL SYSTEM (4JK1/4JJ1)
Engine Controls Schematics
Power Distribution (1)
RTW76EXF003601
X-11
X-11 Heater
relay
1
2
Blower
motor Ignition
switchIgnition
switch Starter
relay
SBF1
Main
120A SBF2
ABS-1
40A SBF3
ABS-2
20A SBF5
IG1
40A SBF4
ECM
40A
SBF6
Blower
30A
EB-13
A/C
10A
2
BLU/
RED
3
BLU/
RED 3
BLU/
RED SBF8
Glow
60A
SBF7
Front
Fog
20A
SBF9
IG2
60A
EB-9
Fog
15A
or
Trailer
20AEB-10
Tail/Illumi
10A
or
Condenser
fan
20A EB-4
Engine
10A
EB-14
4WD
10A EB-15
Horn
10A EB-16
Hazard10A EB-1
ACG
(S)
10AEB-2
ECM
(B)
10AEB-3
F/Pump10A
EB-5 H/L HI(RH)10A Fuse
EB-6 H/L HI(LH)10A Fuse
EB-7 H/L LO(RH)10A Fuse
EB-8 H/L LO(LH)10A Fuse
P-6
Body
Generator P-5
8 BLK/
P-1
P-2
Battery
8
BLK 5WHTSrarter
Srarter
C-3
ELEC IG
10A
Fuse
E-92
0.5 WHT
0.3
BLK 3
WHT/
RED 5
WHT
0.3
BLK 5
RED/
BLU
5
RED
3
WHT/
BLK
30
BLK/
RED
30
BLK/
YEL
P-10
Engine
5
4 X-12
X-12
ECM
Fuel pump relay
ECM
ECM
main
relay
1
2 5
4
X-6
X-6
2
RED/
WHT
0.3
RED/
BLU Fuse/ relay box(Engine room)
2
RED
2
RED
0.5
RED
2
WHT
2
RED/
BLU 2
WHT
2
3 1
5
Lighting
switch Head
lamp
relay
C-36 C-36
RED
P-16
P-15
2nd
Battery
30
BLK/
YEL 30
BLK/
RED
P-10

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