2007 ISUZU KB P190 heater

Engine Cooling – V6 Engine Page 6B1–35

9 To gain easier access to the heater pipe flange and
thermostat housing bolts, disconnect the engine
harness and lay back on the right side of the engine
bay. Apart from those harness connectors removed
during the intake manifold removal, this involves the
removal of wiring harness connectors and fasteners,
as detailed:
a Pull out the release bar (arrows) on each of the ignition coil packs (1) on cylinders 2, 4 and 6,
before disconnecting each connector.
b The coolant temperature sensor.
c The left side Pre-O2 sensor connector, 2, 4 & 6.
NOTE
Refer to 8A – Electrical Body & Chassis for the
location of harness connectors, not shown.

Figure 6B1 –
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–
34
10 Remove the bolt (1) securing the engine harness ground terminal (2), to the cylinder block.
11 Prise both locking legs of the left side engine harness former (4), free, then lift up on the harness former to
release.

Figure 6B1 –
––
–
35
12 W orking at the rear of the engine, disconnect the engine harness to transmission harness connector (1),
as required.
13 Remove the two bolts (2) securing the engine harness former (3) to the rear of the engine.
14 Carefully lift the engine harness free and drape on the right side of the engine.


NOTE
For further information on removing the
thermostat housing and associated components,
refer to 6A1 Engine Mechanical – V6.
Figure 6B1 –
––
–
36

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Engine Cooling – V6 Engine Page 6B1–36

15 Remove the heater pipe assembly (1) to right-hand
side cylinder head (2) attaching bolt (3).
16 Remove the heater pipe assembly to thermostat housing (4) attaching bolts (5), then remove the heater
pipe assembly.
17 Remove and discard the heater pipe assembly to thermostat housing O-ring seals (6).

Figure 6B1 –
––
–
37
18 Remove the three thermostat housing attaching bolts (1), rubber grommets (2), then remove the thermostat
housing (3).
NOTE
The upper thermostat housing attaching bolt is
longer than the two lower bolts.
19 Remove and discard the thermostat housing to engine block gasket (4).

Figure 6B1 –
––
–
38

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Engine Cooling – V6 Engine Page 6B1–38

Install

Always wear protective safety glasses when
working with spring-loaded devices. Failure to
do so could result in eye injury.
1 Install the thermostat into the housing (reverse to removal procedure).
2 Ensure that the engine block and thermostat housing mating surfaces are clean and dry.
3 Install a new gasket to the thermostat housing.
4 Install the thermostat housing to the engine block and secure with the attaching bolts (with rubber grommets installed). Tighten all bolts to the correct torque specification.
Thermostat housing to engine
block bolt torque specification ..............................10 N.m
5 Ensure that the heater pipe assembly and thermostat housing mating surfaces are clean and dry.
6 Install new O-rings to the heater pipe assembly.
7 Install heater pipe assembly to thermostat housing and secure with the attaching bolts. Tighten all bolts to the correct torque specification.
Heater pipe assembly to thermostat
housing bolt torque specification ..........................10 N.m
8 Install heater pipe assembly to right-hand cylinder head bolt. Tighten bolt to the correct torque specification. Heater pipe assembly to cylinder
head bolt torque specification ..............................35 N.m

Always wear protective safety glasses when
working with spring type hose clamps. Failure
to do so could result in eye injury.
9 Reinstall the engine wiring harness, securing the rear harness former to the rear of the engine with the two retaining bolts, tightened to the correct torque specification.
Rear engine harness former
retaining bolts torque specification .......................15 N.m
10 Reinstall the left side engine harness former to the two locating pegs, then push inward to secure.
11 Reinstall the bolt securing the engine harness ground terminal, to the left side of the cylinder block and tighten to the correct torque specification.
Engine harness ground terminal
attaching bolt torque specification ........................12 N.m
12 Reinstall each wiring harness connector to its correct location, ensuring that all security clips are installed correctly.
13 Connect the heater hoses to the heater pipe assembly.
14 Install the coolant inlet pipe. Refer to 3.12 Coolant Inlet Pipe in this Section.
15 Close the radiator drain tap on the lower LHS of the radiator and remove the piece of rubber tubing to the tap outlet.
16 Reinstall the complete intake manifold assembly. Refer to 6A1 Engine Mechanical.
17 Refill cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.

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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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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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Engine Cooling – V6 Engine Page 6B1–66

6 Torque Wrench Specifications
N.m
Coolant Outlet housing to Engine Outlet Attaching Bolts............................... 10
Coolant Pump to Front Cover Attaching Bolts ............................................... 10
Coolant Pump Pulley Attaching Bolts ............................................................ 12
Coolant Inlet Pipe to Thermostat Housing Attaching Bolt .............................. 23
Fan Motor Assembly to Shroud Attaching Screws .......................................... 5
Heater Pipe Assembly to Thermostat Housing Attaching Bolts ..................... 10
Heater Pipe Assembly to Cylinder Head Attaching Bolt ................................ 35
Thermostat Housing to Engine Block Attaching Bolts.................................... 10
Rear Engine Harness .................................................................................... 15
Engine Harness Ground Terminal ................................................................. 12
Coolant Inlet Pipe To Engine Block Bolt ........................................................ 25
Transmission Cooler Lines Bracket .............................................................. 23


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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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Engine Management – V6 – General Information Page 6C1-1–27

4.13 Fuel Rail Assembly
The fuel rail assembly is mounted on the lower intake
manifold and distributes the fuel to each cylinder through
individual fuel injectors. The fuel rail assembly consists of:
• the pipe that carries fuel to each injector,
• a fuel pressure test port,
• six individual fuel injectors,
• wiring harness, and
• wiring harness tray.
Figure 6C1-1 – 31
4.14 Heated Oxygen Sensors
The heated oxygen sensors (HO2S) are mounted in the exhaust system and enable the ECM to measure oxygen
content in the exhaust stream. The ECM uses this information to accurately control the air / fuel ratio, because the
oxygen content in the exhaust gas is indicative of the air / fuel ratio of engine combustion.
W hen the sensor is cold, it produces little or no signal voltage, therefore the ECM only reads the HO2S signal when the
HO2S sensor is warm. As soon as the HO2S are warm and outputting a usable signal, the ECM begins making fuel
mixture adjustments based on the HO2S signals. This is known as closed loop mode.
The HFV6 engine has four HO2S, one LSU 4.2 wide-band planar type HO2S upstream of the catalytic converter in each
exhaust pipe, and one LSF 4.2 two-step planar type HO2S in each exhaust pipe downstream of the catalytic converter.
LSF 4.2 Two-step Planar Heated Oxygen Sensors
The LSF 4.2 two-step planar heated oxygen sensors have
four wires:
• The internal heater element supply, which has 12 V
continually applied whenever the ignition is on.
• Heater element ground – The ECM applies pulse
width modulated (PW M) ground to the HO2S heater
control circuit to control the rate at which the sensor
heats up. This reduces the risk of the sensor being
damaged from heating up too quickly under certain
conditions such as extreme cold temperatures. Once
the sensor has reached the desired operating
temperature, the ECM will monitor and continue to
maintain the sensor temperature.
• Sensor signal to the ECM.
• Sensor ground.
Legend
1 Protective Tube
2 Ceramic Seal Packing
3 Sensor Housing
4 Ceramic Support Tube
5 Planar Measuring Element
6 Protective Sleeve
7 Connection Cable
Figure 6C1-1 – 32

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