2007 ISUZU KB P190 air condition

Engine Cooling – V6 Engine Page 6B1–61

4 Engine Cooling System
Diagnosis
4.1 Poor Heater Operation
Little or no heat coming from the heater, especially at idle could be an indication of a cooling system problem.
As the coolant level begins to get lower than normal, air enters the system to replace the missing coolant. The heater
core is one of the highest parts of the cooling system and therefore, the first area to lose coolant circulation.
At first, with a small amount of coolant loss, lack of heat will be most noticeable at idle. As driving speed increases, the
engine pumps more coolant and more heat is now able to pass through the heater core.
If coolant level drops even lower, heater operation will become less effective, even during normal driving. Cooling and
engine systems can be adversely affected if problem is not corrected before overheating occurs.
4.2 Leaking Cylinder Head Gasket
Combustion gases leaking past the cylinder head gasket can pressurise the cooling system, forcing coolant out of the
system and into the coolant recovery reservoir.
Indications are air bubbles in the coolant or an overflow condition of the recovery reservoir.
4.3 Question the Customer
To avoid needless time and cost in diagnosing cooling system complaints, the customer should be questioned about
driving conditions that place abnormal loads on the cooling system.
1 Is overheating occurring after prolonged idle, in gear, with air conditioning system operating?
If answer is YES – instruct owner on driving techniques that would avoid overheating such as:
• Idle in neutral as much as possible – increase engine rpm to get higher air flow (due to an increase in voltage
to the fan) and coolant flow through the radiator
• Turn air conditioning system off during extended idling periods if overheating is indicated on temperature
gauge. Further diagnostic checks should not be required
2 Is overheating occurring after prolonged driving in slow city traffic, traffic jams, parades, etc?
If answer is YES, explain driving technique to the customer, that would avoid overheating – same as for prolonged idle – No.1. Further diagnostic checks should not be required.
4.4 Diagnostic Chart
If none of the above conditions apply, refer to the following Diagnosis Chart.
To effectively use this chart, question the customer to determine which of the following three categories apply to the
complaint:
1 If complaint is hot indication on temperature gauge.
W as temperature reading accompanied by boiling?
• If answer is YES, go to overheating on diagnosis chart
• If answer is NO, check temperature gauge and sender
2 If complaint is boiling – go to overheating on diagnosis chart.
3 If complaint is coolant loss. Determine if customer is filling the system correctly.
4 If incorrect filling is not the problem, go to coolant loss in the diagnosis chart.

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–62


Refer to 3.1 Service Notes in this Section, for
important safety items before removing the
coolant filler pressure cap or servicing the
system.

The cooling system is designed to operate at
120 –
––
–
130 kPa and a maximum temperature
not above 130 °
°°
°
C.
Cooling System Diagnosis
Step Action Result Yes No
1
Check Temperature gauge reading High Temp.
Low Temp. Go to Step 2
Go to Step 6 –
2
Check drive belt condition and tension. Refer to 6A1
Engine Mechanical. To Specification Go to Step 3 Replace drive
belt or
tensioner.
3 Check coolant Boiling Go to Step 4 Go to Step 5
4 Check coolant level. Refer to 3.2 Coolant
Maintenance in this Section. Low Go to Step 10 Go to Step 6
5
Check coolant filler cap. Refer to 3.7 Pressure
Testing – Coolant Filler Cap Pressure Testing in this
Section OK? Go to Step 8
Replace
Coolant filler
cap
6 Check thermostat. Refer to 3.8 Thermostat in this
Section. OK? Go to Step 9 Go to Step 13
7
Check Engine Coolant Temperature (ECT) sensor.
Refer to 6C1 Engine Management General Information. Faulty Replace Go to Step 12
8
Check cooling fan operation. Refer to 6C1 Engine
Management General Information. Operational Go to Step 10 Repair
9
Check for collapsed upper or lower radiator hose. Collapsed Replace Go to Step 13
10 Visual system check Leaks Go to Step 13 Go to Step 11
11 Check coolant concentration. Refer to 3.2 Coolant
Maintenance. To Specification Go to Step 12 Correct
Concentration Level
12 Check radiator core for bent fins, dirt, bugs or other
obstructions. Obstructed Clean or
straighten Go to Step 14
13
Pressure Test cooling system. Refer to 3.7 Pressure
Testing in this Section. Leaks Repair System OK
14
If none of the above require repair, the problem is
complex or of a major nature.
Refer to 4.5 Problems Not Requiring Disassembly of
Cooling System or 4.6 Problems Requiring Disassembly
of Cooling System. – – –

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–63

4.5 Problems Not Requiring Disassembly of
Cooling System
1 Large obstructions blocking radiator or condenser airflow.
• Auxiliary oil coolers
• License plate
• Obstruction of radiator grille, for example, driving lights or mud
2 Loose, damaged or missing air chute side panels.
3 Missing or damaged air baffle.
4 Cracked or loose coolant recovery system hose.
5 Leaking heater component such as the heater core or water valve.
4.6 Problems Requiring Disassembly of Cooling System
1 Damaged cooling fan or faulty motor operation.
2 Pressure test cooling system.
3 Defective coolant pump.
• Eroded or broken impeller vanes
• Failed bearing or seal – check for shaft or bearing end play
4 Internally blocked radiator core.
5 Obstruction of coolant recovery system.
6 Internal system leaks.
• Head gaskets
• Cracked cylinder block
• Engine front cover
• Intake manifold gaskets
7 Blocked coolant passages in cylinder heads or block – remove cylinder heads and check.
4.7 Black Light and Dye Leak Diagnosis Method
It is strongly recommended that this diagnostic method be used to diagnose fluid leaks. This method is a proven and
reliable method that identifies the specific leak source.
The black light kit can be used for the leak detection of a number of fluids, when used with the appropriate tracer dye.
Examples are: Coolant, Engine Oil, Automatic Transmission Fluid and Air Conditioning Refrigerant (R134A).
The following is a summary of the steps involved in detecting a cooling system fluid leak using black light and dye:
1 Pour specified amount of dye into the cooling system via the coolant filler cap on the outlet housing. Refer 3.1 Service Notes in this Section.
2 Road test the vehicle under normal operating conditions.
3 Direct the light towards the suspect area. The fluid leak will appear as a brightly coloured path leading from the source.
4 Repair fluid leak and recheck to ensure that leak has been rectified.
5 Refer to the manufacturer’s directions when using this method.

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ISUZU KB P190 2007

Fuel System – V6 Page 6C – 3

1 General Information
Description
Fuel is injected into the engine by separate fuel injectors that are mounted in the intake manifold (common chamber).
Fuel is supplied to the injectors under pressure from the fuel tank through the fuel lines and the fuel rail, which is
attached to the top of the common chamber.

A fuel pressure control valve is installed on the fuel rail to maintain fuel line pressure across the injectors under all
operating conditions. Fuel pressure is maintained by controlling the amount of fuel that is supplied from the fuel tank,
based on the demand of the engine via the engine control module (ECM).

Two interchangeable “O” rings are used on the fuel injector and must be replaced when the injectors are removed.
The Multiport Fuel Injection system utilizes an injection system where the injectors turn on at every crankshaft revolution.
The ECM controls the injector on time so that the correct amount of fuel is metered depending on driving conditions.
The V6 engine is designed to use only unleaded petrol.

Unleaded petrol must be used for correct emission control system operation and its use will also minimize spark plug
fouling and extend engine oil life.

Using leaded petrol can damage the emission control system and could void the vehicle warranty. All vehicles are
equipped with an Evaporative Emission Control System. The purpose of the system is to minimize the escape of fuel
vapours into the atmosphere.
Service Precautions
• Use extreme care when working on the fuel system and follow all safety precautions.
• W hen working on the fuel system, disconnect the battery ground cable except for tests where battery voltage is
required.
• Always keep a dry chemical (class B) fire extinguisher near the work area.
• Relace all fuel lines and fittings with the same type of line and fitting as those removed.
• Clean and inspect “O” rings carefully and replace if required.
• Always depressurize the fuel lines before servicing any fuel system components.
• Do not attempt any repairs on the fuel system until, all warnings and instructions, relating to that repair have been
read and ensure all notices and cautions are adhered to.
• Do not allow any naked frames or sparks near the work area when working on the fuel system.
• If draining of the fuel system is required, this should be done in a well ventilated area.
• Protect the fuel lines and associated parts from thermal damage, spattering when welding.

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ISUZU KB P190 2007

Fuel System – V6 Page 6C – 4

1.1 WARNING, CAUTION and NOTES
This Section contains various W ARNINGS, CAUTIONS and NOTE statements that you must observe carefully to reduce
the risk of death or injury during service, repair procedures or vehicle operation. Incorrect service or repair procedures
may damage the vehicle or cause operational faults. W ARNINGS, CAUTION and NOTE statements are not exhaustive.
GM HOLDEN LTD can not possibly warn of all the potentially hazardous consequences of failure to follow these
instructions.
Definition of WARNING, CAUTION and NOTE Statements
Diagnosis and repair procedures in this Section contain both general and specific W ARNING, CAUTION and NOTE
statements. GM HOLDEN LTD is dedicated to the presentation of service information that helps the technician to
diagnose and repair the systems necessary for proper operation of the vehicle. Certain procedures may present a hazard
to the technician if they are not followed in the recommended manner. W ARNING, CAUTION and NOTE statements are
designed to help prevent these hazards from occurring, but not all hazards can be foreseen.
WARNING defined
A W ARNING statement immediately precedes an operating procedure or maintenance practice which, if not correctly
followed, could result in death or injury. A W ARNING statement alerts you to take necessary action or not to take a
prohibited action. If a W ARNING statement is ignored, the following consequences may occur:
• Death or injury to the technician or other personnel working on the vehicle,
• Death or injury to other people in or near the workplace area, and / or
• Death or injury to the driver / or passenger(s) of the vehicle or other people, if the vehicle has been improperly
repaired.
CAUTION defined
A CAUTION statement immediately precedes an operating procedure or maintenance practice which, if not correctly
followed, could result in damage to or destruction of equipment, or corruption of data. If a CAUTION statement is ignored,
the following consequences may occur:
• Damage to the vehicle,
• Unnecessary vehicle repairs or component replacement,
• Faulty operation or performance of any system or component being repaired,
• Damage to any system or components which depend on the proper operation of the system or component being
repaired,
• Faulty operation or performance of any systems or components which depend on the proper operation or
performance of the system or component under repair,
• Damage to fasteners, basic tools or special tools and / or
• Leakage of coolant, lubricant or other vital fluids.
NOTE defined
A NOTE statement immediately precedes or follows an operating procedure, maintenance practice or condition that
requires highlighting. A NOTE statement also emphasises necessary characteristics of a diagnostic or repair procedure.
A NOTE statement is designed to:
• Clarify a procedure,
• Present additional information for accomplishing a procedure,
• Give insight into the reasons for performing a procedure in the recommended manner, and / or
• Present information that gives the technician the benefit of past experience in accomplishing a procedure with
greater ease.



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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–3

1 General Information

The V6 engine management system
incorporates functions and components that
could cause personal injury or vehicle
damage. Refer to 6C1-2 Engine Management –
V6 – Diagnostics, and 6C1-3 Engine
Management – V6 – Service Operations,
before attempting any diagnosis or repairs.
1.1 Introduction
The V6 engine management system is designed to improve engine performance and increase vehicle safety while
meeting the stringent Euro 3 vehicle emission standard. This is achieved by the introduction of the following engine
management sub-systems and components:
• Throttle actuator control (TAC) System – the TAC system allows the engine control module (ECM) to electronically
control the throttle plate opening eliminating the need for the following components:
• mechanical link between the throttle plate and accelerator pedal,
• cruise control module, and
• idle air control motor.
Refer to 3.5 Throttle Actuator Control System for details of the TAC System operation and to 3.6 Cruise Control System for details of the cruise control operation.
This feature results in improved driveability, better fuel economy and emission control.
• W ide band heated oxygen sensor provides a more accurate measurement of the oxygen concentration in the
exhaust gas. Refer to 4.14 Heated Oxygen Sensors.
• Dual spray fuel injectors are now used. The use of this spray pattern is used in engines with two intake valves per
cylinder. The dual spray is achieved by having two openings in the spray orifice disc that are arranged in such a
way that two fuel sprays result, being aimed at each intake valve port. Refer to 4.12 Fuel Injectors.
• Pencil Coil – allows the ignition coil to be fitted directly on the spark plug eliminating the need for spark plug wires.
Refer to 4.15 Ignition Coil and Spark Plug.
The engine management system has a self diagnostic capability, as well as connections to enable diagnosis of faults. If
the ECM recognises operational problems it can alert the driver via the malfunction indicator lamp (MIL) in the instrument
cluster. The ECM also interfaces with other systems in the vehicle as required.
For further information on the air-conditioning system refer to 2A Heater and Air-conditioning,
For the location of fuses, fusible links and relays, refer to 8A Electrical-Body and Chassis.
1.2 Emission Control
ADR 79/01 Emissions Standards
MY2006 I190 Rodeo has been configured to comply with Australian Design Rule 79/01, that adopts the technical
requirements of the European Council Directive 98/69/EC. Commonly referred to as “Euro 3”, the new legislation
modifies the exhaust emissions, compared to the existing ADR 37/01 (or ‘Euro 2’) vehicle emissions standards.
Australian Design Rule 79/01 implements the 'Euro 3' exhaust and evaporative emissions requirements for petrol fuelled
passenger cars, forward control vehicles and passenger off-road vehicles with a gross vehicle mass (GVM) up to 3.5
tonnes. All new vehicles within these categories and first registered from January 1, 2006 must comply with ADR 79/01.
The next table shows a comparison between the existing ADR 37/01 (‘Euro 2’) and ADR 79/01 (‘Euro 3’) Hydrocarbons
Carbon
Monoxide (g/km) Exhaust
(g/km) Evaporative
(g/test) Oxides of Nitrogen
(g/km) Particulate
Matter (g/test)

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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–4

ADR 37/01 (Petrol) 2.1 0.26 2 0.63 Not Applicable
ADR 79/01 (Petrol,
LPG, CNG) 2.3 0.2 2 0.15 0.05
1.3 Warning Caution and Notes
This Section contains various W ARNINGS, CAUTIONS and NOTE statements that you must observe carefully to reduce
the risk of death or injury during service, repair procedures or vehicle operation. Incorrect service or repair procedures
may damage the vehicle or cause operational faults. W ARNINGS, CAUTION and NOTE statements are not exhaustive.
GM Holden LTD can not possibly warn of all the potentially hazardous consequences of failure to follow these
instructions.
Definition of WARNING, CAUTION and NOTE Statements

Diagnosis and repair procedures in this Section contain both general and specific W ARNING, CAUTION and NOTE
statements. GM Holden LTD is dedicated to the presentation of service information that helps the technician to diagnose
and repair the systems necessary for proper operation of the vehicle. Certain procedures may present a hazard to the
technician if they are not followed in the recommended manner. W ARNING, CAUTION and NOTE statements are
designed to help prevent these hazards from occurring, but not all hazards can be foreseen.
WARNING defined
A W ARNING statement immediately precedes an operating procedure or maintenance practice which, if not correctly
followed, could result in death or injury. A W ARNING statement alerts you to take necessary action or not to take a
prohibited action. If a W ARNING statement is ignored, the following consequences may occur:
• Death or injury to the technician or other personnel working on the vehicle,
• Death or injury to other people in or near the workplace area, and / or
• Death or injury to the driver / or passenger(s) of the vehicle or other people, if the vehicle has been improperly
repaired.
CAUTION defined
A CAUTION statement immediately precedes an operating procedure or maintenance practice which, if not correctly
followed, could result in damage to or destruction of equipment, or corruption of data. If a CAUTION statement is ignored,
the following consequences may occur:
• Damage to the vehicle,
• Unnecessary vehicle repairs or component replacement,
• Faulty operation or performance of any system or component being repaired,
• Damage to any system or components which depend on the proper operation of the system or component being
repaired,
• Faulty operation or performance of any systems or components which depend on the proper operation or
performance of the system or component under repair,
• Damage to fasteners, basic tools or special tools and / or
• Leakage of coolant, lubricant or other vital fluids.
NOTE defined
A NOTE statement immediately precedes or follows an operating procedure, maintenance practice or condition that
requires highlighting. A NOTE statement also emphasises necessary characteristics of a diagnostic or repair procedure.
A NOTE statement is designed to:
• Clarify a procedure,
• Present additional information for accomplishing a procedure,
• Give insight into the reasons for performing a procedure in the recommended manner, and / or
• Present information that gives the technician the benefit of past experience in accomplishing a procedure with
greater ease.

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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–5

2 Component Locations
2.1 Cylinder Numbering
Engine cylinder identification follows the international
standard OBD II. This standard calls for the engine cylinder
bank number one to be identified by the location of cylinder
number one. Therefore the numbering for the V6 engine is:
The V6 engine cylinders are numbered as follows:
• 1, 3, 5 – Right-hand side (Bank 1),
• 2, 4, 6 – Left-hand side (Bank 2).
The engine firing order is 1, 2, 3, 4, 5, 6.

Figure 6C1-1 – 1
2.2 Engine Compartment
Legend
1 Mass Air Flow (MAF) Sensor 2 Air-conditioner Refrigerant Pressure Sensor
Figure 6C1-1 – 2

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