2007 ISUZU KB P190 Circuit

ENGINE DIAGNOSIS (C24SE) 6-11
Abnormal Combustion
Condition Possible cause Correction
Trouble in fuel injection system Fuel pressure control valve
defective Replace

Fuel filter clogged Replace
Fuel pump clogged Clean or replace
Fuel tank or fuel pipe clogged Clean or replace
Fuel injector clogged Clean or replace
Fuel pump relay defective Replace
Power supply cable for fuel pump
loosely connected or defective Reconnect, correct or replace

Manifold Absolute Pressure
Sensor circuit open or shorted Correct or replace

Manifold Absolute Pressure
Sensor defective Replace

Engine Coolant Temperature
(ECT) Sensor circuit open or
shorted Correct or replace

ECT Sensor defective Replace
Throttle Position Sensor
adjustment incorrect Reconnect

Throttle Position Sensor defective Replace
Throttle Position Sensor
connector loosely connected Reconnect

Vehicle Speed Sensor cable
loosely connected or defective Correct or replace

Vehicle Speed Sensor loosely
fixed Fix tightly

Vehicle Speed Sensor in wrong
contact or defective Replace

Engine Control Module cable
loosely connected or defective Correct or replace
Trouble in emission control
system Heated Oxygen Sensor circuit
open (If applicable) Correct or replace

Heated Oxygen Sensor defective
(If applicable) Replace

Signal vacuum hose loosely fitted
or defective Correct or replace

ECT Sensor circuit open or
shorted Correct or replace

ECT Sensor defective Replace
Evaporative Emission Control
system (If applicable) Refer to Section 6E
Trouble in ignition system
- Refer to "Engine Lacks Power"
Trouble in cylinder head parts Carbon deposits in combustion
chamber Remove carbon

Carbon deposit on valve, valve
seat and valve guide Remove carbon


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ISUZU KB P190 2007

6-14 ENGINE DIAGNOSIS (C24SE)
Malfunction Indicator Lamp
The instrument panel "CHECK ENGINE" Malfunction
Indicator lamp (MIL) illuminates by self diagnostic
system when the system checks the starting of
engine, or senses malfunctions.
Condition Possible cause Correction
"CHECK ENGINE" MIL does not
illuminate at the starting of engine Bulb defective Replace

MIL circuit open Correct or replace
Command signal circuit to operate
self diagnostic system shorted Correct or replace

Engine Control Module (ECM)
cable loosely connected,
disconnected or defective Correct or replace
ECM
defective Replace
“CHECK ENGINE” MIL
illuminates, and stays on Deterioration heated oxygen
sensor of internal element Replace

Heated oxygen sensor connector
terminal improper contact
(If applicable) Reconnect properly

Heated oxygen sensor lead wire
shorted (If applicable) Correct

Heated oxygen sensor circuit
open (If applicable) Correct or replace

Deterioration engine coolant
temperature sensor of internal
element Replace

Engine coolant temperature
sensor connector terminal
improper contact Reconnect properly

Engine coolant temperature
sensor lead wire shorted Correct

Engine coolant temperature
sensor circuit open Correct or replace

Throttle position sensor open or
shorted circuits Correct or replace

Deterioration of crankshaft
position sensor Replace

Crankshaft position sensor circuit
open or shorted Correct or replace

Vehicle speed sensor circuit open Correct or replace
Manifold absolute pressure sensor
circuit open or shorted Correct or replace

Intake air temperature sensor
circuit open or shorted Correct or replace

Fuel injector circuit open or shorted Correct or replace
ECM driver transistor defective Replace EPROM or ECM
Malfunctioning of ECM RAM
(Random Access Memory) or
Malfunctioning of ECM PROM
(Programmed Read Only Memory) Replace EPROM or ECM


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ISUZU KB P190 2007

ENGINE MECHANICAL (C24SE) 6A-5
General Information on Engine Service
The following information on engine service should be noted carefully, as it is important in preventing damage and
contributing to reliable engine performance:
z W hen raising or supporting the engine for any reason, do not use a jack under the oil pan. Due to the small
clearance between the oil pan and the oil pump strainer, jacking against the oil pan may cause damage to the
oil pick up unit.
z The 12-volt electrical system is capable of damaging circuits. W hen performing any work where electrical
terminals could possible be grounded, the ground cable of the battery should be disconnected at the battery.
z Any time the intake air duct or air cleaner is removed, the intake opening should be covered. This will protect
against accidental entrance of foreign material into the cylinder which could cause extensive damage when
the engine is started.

Cylinder Block
The cylinder block is made of cast iron. The crankshaft is supported by five bearings. The bearing cap is made of
nodular cast iron.

Cylinder Head
The cylinder head is made of aluminum alloy casting with a spark plug in the center.

Valve Train
Valve system is a single over head camshaft.
The valves clearance adjustment are hydraulic.
Hydraulic valve lifter adjustment, no adjustment necessary.

Intake Manifold
The intake manifold is made of aluminum alloy.

Exhaust Manifold
The exhaust manifold is made of high Si-Mo nodular iron.

Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade that meets the cylinder bore diameter. Each piston has two
compression rings and one oil ring. The piston pin is made of cast hardened steel. The connecting rod bearings are
made of modular cast iron. The connecting rod bearings are made of steel backed with tri-metal babbitt metal.

Crankshaft and Bearings
The crank shaft is made of modular cast iron. Pins and journal are graded for correct size selection for their bearing.


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ISUZU KB P190 2007

6B-2 ENGINE COOLING
General Description
Legend
1 W ater Pump
2 Thermostat
3 Radiator
4 Reserve Tank 5 Coolant Distributor
6 Cylinder Block and Head
7 Throttle Body
8 Heater




The Cooling System is a pressurized type, where the water
pump, which is cambelt driven, forces the circulation of
the coolant through the cylinder block and head. The
thermostat regulates the flow of coolant between the
radiator and the bypass circuit. The heater is part of the
bypass circuit. The throttle body pre-heat is a separate
circuit which is not regulated by the thermostat. An oil
cooler may be fitted as part of this circuit.


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ISUZU KB P190 2007

ENGINE COOLING 6B-5
Diagnosis
Engine Cooling Trouble
Condition Possible cause Correction
Engine overheating Low Engine Coolant level Replenish
Thermo mater unit faulty Replace
Faulty thermostat Replace
Faulty Engine Coolant temperature
sensor Repair or replace

Clogged radiator Clean or replace
Faulty radiator cap Replace
Low engine oil level or use of
improper engine oil Replenish or change oil

Clogged exhaust system Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position
sensor circuit Repair or replace

Damaged cylinder head gasket Replace
Loosen V-belt tension Adjust belt tension or replace.
Collapsed hoses Replace
Faulty Fan clutch Replace
Engine overcooling Faulty thermostat Replace
Engine slow to warm-up Faulty thermostat Replace
Thermo unit faulty Replace


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ISUZU KB P190 2007

ENGINE ELECTRICAL 6D1-5











































Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your eyes, skin,
fabric, or a painted surface, immediately and thoroughly rinse
the affected area with clean tap water.
Never allow metal tools or jumper cables to come in contact
with the positive battery terminal, or any other metal surface of
the vahicle. This will protect against a short circuit.
Always keep batteries out of reach of young children.
Jump Starting Procedure
1. Set the vehicle parking brake and place the shift lever in the
"NEUTRAL" position.
Turn "OFF" the ignition.
Turn "OFF" all lights and any other accessory requiring electrical power.
2. Look at the built-in hydrometer.
If the indication area of the built-in hydrometer is completel
y
clear, do not try to jump start.
3.
Attach the end of one jumper cable to the positive terminal
of the booster battery.

Attach the other end of the same cable to the positive
terminal of the discharged battery.
Do not allow the vehicles to touch each other. This will cause a ground connection, effectively neutralizing the
charging procedure.
Be sure that the booster battery has a 12 volt rating.
4.
Attach one end of the remaining cable to the negative
terminal of the booster battery.
Attach the other end of the same cable to a solid engine ground (such as the air conditioning compressor bracket o
r
the generator mounting bracket) of the vehicle with the
discharged battery.
The ground connection must be at least 450 mm (18 in.) from the battery of the vehicle whose battery is being
charged.
WARNING: NEVER ATTACH THE END OF THE JUMPER
CABLE DIRECTLY TO THE NEGATIVE TERMINAL OF THE
DEAD BATTERY.
5. Start the engine of the vehicle with the good battery.
Make sure that all unnecessary electrical accessories have been turned "OFF".
6. Start the engine of the vehicle with the dead battery.
7. To remove the jumper cables, follow the above directions in reverse order.
Be sure to first disconnect the negative cable from the vehicle with the discharged battery.


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ISUZU KB P190 2007

6D3-2 STARTING AND CHARGING SYSTEM


Starting System
General Description
Cranking Circuit
The cranking system consists of a battery, starter, starter
switch, starter relay, etc. These main components are
connected.
Starter
The cranking system employs a magnetic type reduction
starter in which the motor shaft is also used as a pinion shaft.
W hen the starter switch is turned on, the contacts of magnetic
switch are closed, and the armature rotates. At the same time,
the plunger is attracted, and the pinion is pushed forward by
the shift lever to mesh with the ring gear.
Then, the ring gear runs to start the engine. W hen the engine
starts and the starter switch is turned off, the plunger returns,
the pinion is disengaged from the ring gear, and the armature
stops rotation. W hen the engine speed is higher than the
pinion, the pinion idles, so that the armature is not driven.




Service Precaution
CAUTION:
Always use the correct fastener in the proper location.
When you replace a fastener, use ONLY the exact part
number for that application. ISUZU will call out those
fasteners that require a replacement after removal. ISUZU
will also call out the fasteners that require thread lockers
or thread sealant. UNLESS OTHERWISE SPECIFIED, do
not use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or fastener
joint interfaces. Generally, such coatings adversely affect
the fastener torque and the joint clamping force, and may
damage the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following
these instructions can help you avoid damage to parts
and systems.

Diagnosis
Condition Possible cause Correction
Starter does not run Charging failure Repair charging system
Battery Failure Replace Battery
Terminal connection failure Repair or replace terminal connector
and/or wiring harness
Starter switch failure Repair or replace starter switch
Starter failure Repair or replace starter


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ISUZU KB P190 2007

6D3-8 STARTING AND CHARGING SYSTEM
General On-Vehicle Inspection
The operating condition of charging system is indicated by the
charge warning lamp. The warning lamp comes on when the
starter switch is turned to "ON" position. The charging system
operates normally if the lamp goes off when the engine starts.
If the warning lamp shows abnormality or if undercharged or
overcharged battery condition is suspected, perform diagnosis
by checking the charging system as follows:
1. Check visually the belt and wiring connector.
2. W ith the engine stopped, turn the stator switch to "ON" position and observe the warning lamp.
If lamp does not come on:
Disconnect wiring connector from generator, and ground the terminal "L" on connector side.
If lamp comes on:
Repair or replace the generator.




Generator
Removal
1. Disconnect battery ground cable.
2. Move drive belt tensioner to loose side using wrench then remove drive belt.
3. Disconnect terminal "B" wiring connector and connector.
4. Remove generator assembly.

Generator Power and Circuit Diagram


Inspection
Legend
1 Load resistor, set parallel to battery
2 Battery
3 Voltmeter
4 Ammeter
5 Ignition Lock
6 Charge Telltale
7 Generator

1. Disconnect battery.
2. Close off connecting cable from alternator terminal "B+".
3. Set ammeter (measuring range 100A) in disconnected line.
4. Connect controllable load resistor to battery terminal.
5. Set resistor in front of connection to "O"; connect first to battery, then to resistor.
6. Connect tachometer.
7. Connect oscilloscope according to manufacturer's instructions.
8. Connect battery.
9. Start engine and read off resulting current at various engine speeds.


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ISUZU KB P190 2007