2007 ISUZU KB P190 cooling

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

Engine Cooling – V6 Engine Page 6B1–64

5 Specifications
General
Coolant Filler Cap Pressure Rating .............................................................................120 kPa
Cooling System Capacity
Automatic Transmission ........................................................................................ 9.9 litres
Manual Transmission .......................................................................................... 10.3 litres
Coolant Corrosion Inhibitor Quantity W hen Refilling System Automatic Transmission Models......................................................................... 5 litres
Manual Transmission Models .......................................................................... 5.2 litres
NOTE
DEX-COOL® long life coolant or equivalent such
as Extended Life Anti-freeze Coolant, conforming
to GM Specification 6277M, must be used when
changing coolant.
Thermostat Type...............................................................................................Power element (wax pellet)
Start to Open at ......................................................................................................... 82 ± 2 ° C
Fully Open at .......................................................................................................... 95° C ma x.
Coolant Pump
Type........................................................................................................................ Cen trifugal
Drive ................................................................................................ Multi-Vee Serpentine Belt
Bearing Type .................................................................................... Double Row Ball Bearing
Radiator
Core type ......................................................................................... Aluminium crossflow core
Overall width ................................................................................................................ 66 4 mm
Core width.................................................................................................................... 5 10 mm
Overall height............................................................................................................... 60 2 mm
Core height .................................................................................................................. 51 2 mm
Core thickness ............................................................................................................... 27 mm
Plastic Tanks .............................................................................. Nylon 6.6 (30% Glass Filled)
Radiator Hoses Lower Upper
Number ............................................................................... One............................. One
Type................................................................................ Moulded ...................... Moulded
Inside diameter ................................................................. 34 mm ........................ 34 mm

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–65

Engine Cooling Fan

Rotational Speed (with 13 ± 0.26 volts negative polarity duty signal applied)

– Stage 1 (25% Duty) ..................... 1,100 ± 110 rpm (3 ± 0.3A)
– Stage 2 (25% Duty) ..................... 1,600 ± 160 rpm (7 ± 0.7A)
– Stage 3 (25% Duty) ..................... 2,100 ± 210 rpm (15 ± 1.5A)
– Stage 4 (25% Duty) ..................... 2,400 ± 240 rpm (22 ± 2.2A)


Number of Blades ............................................................................................................... .... 5
Fan – Design ................................................................. Asymmetrical spaced, curved blades
Material ................................................................................... Nylon Glass, Mineral reinforced
Diameter ...................................................................................................................... 5 00 mm
Fan Motor – Type ..................................................................................................... Brushless
Fan Motor – Power ......................................................................................................... 400W
Fan Motor – Input signal ................................................................................................ 100Hz
Housing ..........................................................Semi-sealed, zinc-coated steel with drain hole
Direction of Rotation .....................................Counter clockwise (as viewed from drivers seat)

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ISUZU KB P190 2007

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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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–67

7 Special Tools
Tool number Illustration Description Classification
AU505
Coolant Tester
Used for testing the coolant
concentration level.
Previously released. Mandatory
AU525
Quick Connect Release Tool
Used to release the quick connect
fittings on automatic transmission fluid
cooler lines at the radiator end, when
fitted.
Previously released. Mandatory
BT3373–F

Belt Tension Gauge
Used when checking drive and
accessory belt tension and
adjustments.
Previously released. Desirable
J 26568 Refractometer
Used for testing coolant concentration
level.
Previously released, as AU 435. Mandatory
J28431–B Fluid Dye
Available in 24 x 1-ounce bottles.
Used in conjunction with a black light
such as J42220 to locate the source
of various fluid leaks.
Previously released. Desirable
J42220 Black Light, Leak Detection Lamp
Used with dye, J28431–B to locate the
source of various vehicle fluid leaks.
Previously released. Desirable
N/A Cooling System Pressure Tester
Previously released. Commercially available. Mandatory


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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–2

3.9 Serial Data Communication System ................................................................................................................... 17
3.10 Self Diagnostics System ..................................................................................................................................... 17
3.11 Service Programming System ..................................................................................................... ....................... 17
3.12 Immobiliser System ............................................................................................................................................. 18
4 Component Description and Operation ............................................................................................ .19
4.1 A/C Refrigerant Pressure Sensor ....................................................................................................................... 19
4.2 Brake Pedal Switch Assembly ............................................................................................................................ 19
Stop Lamp and Initial Brake Apply Switch ....................................................................................... ................. 19
Stop Lamp Switch ............................................................................................................................................ 19
Initial Brake Apply Switch ..................................................................................................... ............................ 19
4.3 Barometric Pressure Sensor..................................................................................................... .......................... 20
4.4 Camshaft Position Sensor .................................................................................................................................. 20
4.5 Crankshaft Position Sensor ................................................................................................................................ 21
4.6 Clutch Pedal Switch Assembly – Manual Vehicles Only ............................................................................ ...... 22
4.7 Engine Control Module........................................................................................................................................ 22
4.8 Engine Coolant Temperature Sensor .............................................................................................. ................... 23
4.9 Electric Cooling Fans .......................................................................................................................................... 23
4.10 Engine Oil Level and Temperature Sensor ........................................................................................ ................ 24
Engine Oil Temperature Sensor ......................................................................................................................... 24
Engine Oil Level Sensor ...................................................................................................................................... 25
4.11 Engine Oil Pressure Sensor..................................................................................................... ........................... 25
4.12 Fuel Injectors........................................................................................................................................................ 26
4.13 Fuel Rail Assembly ............................................................................................................. ................................. 27
4.14 Heated Oxygen Sensors .......................................................................................................... ............................ 27
LSF 4.2 Two-step Planar Heated Oxygen Sensors .................................................................................. ......... 27
LSU 4.2 Wide-band Planar Heated Oxygen Sensors ................................................................................. ....... 29
4.15 Ignition Coil and Spark Plug ............................................................................................................................... 31
4.16 Intake Air Temperature Sensor .................................................................................................. ......................... 32
4.17 Knock Sensor ....................................................................................................................................................... 32
4.18 Mass Air Flow Sensor........................................................................................................... ............................... 33
Air Intake System ................................................................................................................................................. 33
Mass Air Flow Sensor........................................................................................................... ............................... 33
Construction ..................................................................................................................................................... 34
Operation ......................................................................................................................................................... 34
5 Abbreviations and Glossary of Terms ............................................................................................ ...35

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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–12

Battery Voltage Correction Mode
The ECM monitors the battery voltage circuit to ensure the voltage available to the engine management system stays
within the specified range. A low system voltage changes the voltage across the fuel injectors, which affects the fuel
injector flow rate. In addition, a low system voltage fault condition may cause other engine management system
components to malfunction.
The ECM switches to battery voltage correction mode when the ECM detects a low battery voltage fault condition. W hile
in battery voltage correction mode, the ECM performs the following functions to compensate for the low system voltage:
• Increases the injector on-time to maintain the correct amount of fuel being delivered, and
• Increases the idle speed to increase the generator output.
Limp Mode
The programming in the ECM software allows the engine to run in a back-up fuel strategy or limp mode when the ECM
fails to receive signal inputs from critical sensors or when a critical engine management fault condition exists.
The ECM switches to limp mode to enable the vehicle to be driven until service operations can be performed.
Engine Protection Mode
Engine protection mode is engaged to protect engine components from friction damage in the event of an engine over-
temperature condition being detected by the ECM.
W hen the ECM is in engine protection mode, fuel injectors are systematically disabled and re-activated. The injectors
that have been shut down allow the air being drawn into the engine to assist with engine cooling.
Clear Flood Mode
If the engine is flooded with fuel during starting and will not start, the clear flood mode can be manually selected by
depressing the accelerator pedal to wide open throttle (W OT). In this mode, the ECM will completely disable the fuel
injectors, and will maintain this state during engine cranking as long as the ECM detects a W OT condition with engine
speed less than 1,000 rpm.
3.3 Ignition Control System
The electronic ignition system provides a spark to ignite the compressed air / fuel mixture at the correct time. The ECM
maintains correct spark timing and dwell for all engine operating conditions. The ECM calculates the optimum spark
parameters from information received from the various sensors and triggers the appropriate ignition module / coil to fire
the spark plug.
3.4 Starter Motor Operation
The engine control module controls the activation of the start relay in response to inputs from:
• Ignition switch,
• Battery,
• Immobiliser system, and
• Automatic transmission gear selector position / clutch pedal position switch for vehicles with manual transmissions.
3.5 Throttle Actuator Control System
Description
The throttle actuator control (TAC) system is used to improve emissions, fuel economy and driveability. The TAC system
eliminates the mechanical link between the accelerator pedal and the throttle plate and eliminates the need for a cruise
control module and idle air control motor. The TAC system comprises of:

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ISUZU KB P190 2007

Engine Management – V6 – General Information Page 6C1-1–19

4 Component Description and
Operation
4.1 A/C Refrigerant Pressure Sensor
The engine control module (ECM) applies a positive 5 V reference voltage and ground to the air-conditioner (A/C)
refrigerant pressure sensor. The A/C refrigerant pressure sensor provides signal voltage to the ECM that is proportional
to the A/C refrigerant pressure. The ECM monitors the A/C refrigerant pressure sensor signal voltage to determine the
refrigerant pressure.
• The A/C refrigerant pressure sensor voltage increases as the refrigerant pressure increases.
• W hen the ECM detects the refrigerant pressure exceeds a predetermined value, the ECM activates the cooling
fans to reduce the refrigerant pressure.
• W hen the ECM detects the refrigerant pressure is too high or too low, the ECM disables the A/C clutch to protect
the A/C compressor from damage.
4.2 Brake Pedal Switch Assembly
Stop Lamp and Initial Brake Apply Switch
The stop lamp and initial brake apply switch assembly (1) is
located on the brake pedal support.
The engine control module (ECM) uses the brake pedal
switch inputs to determine when the brake pedal is
depressed.
The ECM uses the two break pedal switch inputs for:-
• Enabling cruise control,
• Brake torque management,
• Cross referencing the stop lamp switch against the
initial brake apply switch for correct operation.
For further information on brake torque management,
refer to 3.7 Brake Torque
Management.
For further information on the cruise control system, refer to
3.6 Cruise Control System.
Figure 6C1-1 – 13
Stop Lamp Switch
The stop lamp switch contacts are normally open with the brake pedal at rest and closed when the brake pedal is
depressed.
Initial Brake Apply Switch
The initial brake apply switch contacts are normally closed with the brake pedal at rest and open when the brake pedal is
depressed.


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ISUZU KB P190 2007