sensor ISUZU KB P190 2007 Workshop Repair Manual

Engine Management – V6 – General Information Page 6C1-1–30

Similar to the two-step HO2S, measurement is achieved by
comparing the oxygen content of the exhaust gas to the
oxygen content of a reference gas. However, the way in
which the ECM calculates the exhaust oxygen content is
different, and results in a continual signal. This allows the
ECM to monitor not only whether the fuel mixture is rich or
lean, but exactly how rich or how lean. The wide-band
HO2S is basically a two-step HO2S with the addition of a
pump cell.
The ECM applies a pump voltage across the pump cell,
which causes oxygen to be pumped from the exhaust gas
into or out of the diffusion gap through the diffusion barrier.
W hile monitoring the Nernst cell, the ECM varies the pump
current so the gas in the diffusion gap remains constant at
an A/F ratio of 14.7:1 (Nernst cell output of 450 mV).
Legend
1 Outer Electrode
2 Inner Electrode
3 Heater Element
4 Oxygen Molecule (in exhaust stream)
5 Other Molecules (in exhaust stream)
6 Reference Gas (outside air)
7 Nernst Cell
8 Pump Cell Electrode
9 Pump Cell Electrode
10 Pump Cell
11 Diffusion Gap
12 Porous Diffusion Barrier
A Pump Current
V Nernst Cell Voltage
Figure 6C1-1 – 36
If the exhaust gas is lean, the pump cell pumps oxygen to
the outside (positive pump current). If the exhaust gas is
rich, oxygen is pumped from the exhaust gas into the
diffusion gap (negative pump current). By monitoring how
much it has to vary the pumping current, the ECM
determines the exact A/F ratio.
Legend
A Rich Mixture
B A/F Ratio 14.7:1 (Lambda = 1)
C Lean Mixture
D Sensor Current
Figure 6C1-1 – 37

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Engine Management – V6 – General Information Page 6C1-1–31

4.15 Ignition Coil and Spark Plug
Long-life platinum tip spark plugs are used which, along with
the ignition coil spark plug boot and spring, require
replacement at 100,000 kilometre service intervals. The
spark plugs, featuring a J-gap and a conical seat, do not
require inspection between services, and must not be re-
gapped.
Individual pencil-type ignition coils, one for each cylinder, are
mounted in the centre of the camshaft covers, and have
short boots connecting the coils directly to the spark plugs.
The pencil coil makes use of the space available in the spark
plug cavity in the cylinder head and camshaft cover. As a
pencil coil is always mounted directly on to the spark plug,
no high-tension ignition leads are required, further enhancing
reliability.

Figure 6C1-1 – 38
Pencil coils operate similarly to other compact coils, however
due to their shape, the structure differs considerably.
The central rod core (1) consists of laminations of varying
widths, stacked in packs that are nearly spherical. A yoke
plate (2), made from layered electrical sheet steel, provides
the magnetic circuit. The primary winding (3) is located
around the secondary winding (4), which supports the core.
A printed circuit board, or driver module, (5) is located at the
top of the coil and controls the firing of the coil based on
input from the ECM.
The ECM is responsible for maintaining correct spark timing
and dwell for all driving conditions. The ECM calculates the
optimum spark parameters from information received from
the various sensors, and triggers the appropriate ignition
module which then operates the coil.
The ignition coil / modules are supplied with the following
circuits:
• Ignition feed circuit.
• Ground circuit.
• Ignition control circuit.
• Reference low circuit.

Figure 6C1-1 – 39

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Engine Management – V6 – General Information Page 6C1-1–32

4.16 Intake Air Temperature Sensor
The intake air temperature (IAT) sensor is a thermistor,
which is a resistor that changes it’s resistance value based
on temperature.
The IAT sensor is part of the air mass sensor and is not a
serviceable item. The sensor is a negative temperature
coefficient (NTC) type, intake air temperature produces a
high sensor resistance while high engine coolant
temperature causes low sensor resistance.
Legend
A Temperature
B Resistance
The ECM provides a 5 V reference signal to the IAT and
monitors the return signal which enables it to calculate the
intake air temperature.
The ECM uses this signal to make corrections to the
operating parameters of the system based on changes in air
intake temperature.
Figure 6C1-1 – 40
4.17 Knock Sensor
The knock sensor (KS) signal is used by the ECM to provide
optimum ignition timing while minimising engine knock or
detonation.
The ECM monitors the voltage of the left-hand (Bank 2)
sensor during the 45 degrees after cylinder 2, 4, or 6 has
fired and the voltage of the right-hand (Bank 1) sensor
during the 45 degrees after cylinder 1, 3, or 5 has fired.
If knock occurs in any of the cylinders, the ignition will be
retarded by three degrees for that particular cylinder. If the
knocking then stops, the ignition will be restored to what it
was before in steps of 0.75 degrees.
Should knocking continue in the same cylinder despite of
the ignition being retarded, the ECM will retard the ignition
an additional step of three degrees, and so on, up to a
maximum of 12.75 degrees. The ignition will also be
retarded at high ambient temperatures to counteract
knocking tendencies provoked by high intake air
temperatures.
Should either Bank 1 or Bank 2 sensor fail to work, or
should an open circuit occur, the ignition timing will then be
set at a default strategy that will retard the ignition much
more than normal.
Figure 6C1-1 – 41

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Engine Management – V6 – General Information Page 6C1-1–33

The knock sensor is tuned to detect the frequency of the
vibration created by combustion knock. The vibration is
transferred to the knock sensor through the cylinder
block (1).
Inside the sensor is a mass (2) that is excited by this
vibration, and the mass exerts a compressive force onto a
piezo-ceramic element (3). The compressive force causes a
charge transfer inside the element, so that an AC voltage
appears across the two outer faces (4) of the element. The
amount of the AC voltage produced is proportional to the
amount of knock.
Figure 6C1-1 – 42
4.18 Mass Air Flow Sensor
Air Intake System
The air intake system draws outside air through an air
cleaner assembly (1). The air is then routed through a mass
air flow (MAF) sensor (2) and into the throttle body and
intake manifold. The air is then directed into the intake
manifold runners, through the cylinder heads and into the
cylinders.
An arrow marked on the body of the MAF sensor indicates
correct air flow direction. The arrow must point toward the
engine.
Figure 6C1-1 – 43
Mass Air Flow Sensor
A hot film type mass air flow (MAF) sensor is used which
measures the air mass inducted into the engine, regardless
of the engine’s operating state. The MAF precisely
measures a portion of the total airflow and takes into
account the pulsation and reverse flows generated by the
engine’s inlet and exhaust valves.
Changes in intake air temperature have no effect on
measuring accuracy.
Figure 6C1-1 – 44

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Engine Management – V6 – General Information Page 6C1-1–34

Construction
Projecting into the MAF sensor body is the compact design
sensor assembly (1), which consists of:
• the sensor element (2),
• partial airflow measuring tube (3), and
• integrated evaluation electronics (4).
Figure 6C1-1 – 45
Operation
A diaphragm (1) on the sensor element (2) is heated by a
centrally mounted heater resistor (3), which is held at a
constant temperature. The temperature drops sharply each
side of the heating zone.
Temperature of the diaphragm is registered to the
evaluation electronics by two temperature-dependent
resistors located on the upstream (4) and downstream (5)
side of the resistor.
W ith no air flow through the air flow measuring tube and
over the sensor element, the temperature characteristic is
the same each side of the heating zone and the resistance
values are identical.
As air flows over the sensor element, the upstream resistor
value alters due to the cooling effect of the air flow. As the
air flows over the heating zone the air temperature is
increased.
Figure 6C1-1 – 46
The air then passes over the downstream resistor and alters the resistance value, but as the air temperature is higher,
the value is different to the upstream resistor. This change in temperature creates a temperature differential between the
two resistors.
It is this differential that is used to calculate the air mass flow, which is independent of absolute temperature. The
differential is also directional, which means the MAF not only measures the mass of the incoming air, but also its
direction.
As the evaluation electronics are measuring the resistance differential between the resistors, the air mass flow for the
entire amount of air passing through the MAF is calculated and sent to the ECM as an analogue signal of 0 – 5 V.
The ECM can also detect air flow that is inappropriate for a given operating condition based on the signal voltage, or a
signal that appears to be fixed based on the lack of normal signal fluctuations expected during engine operation.
Tech 2 can display the MAF value in grams per second (g/s). Values should change rather quickly on acceleration, but
should remain fairly stable at any given engine speed.

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Engine Management – V6 – General Information Page 6C1-1–35

5 Abbreviations and Glossary of
Te r m s
Abbreviations and terms used in this Section are listed below in alphabetical order with an explanation of the
abbreviation or term.
Abbreviation Description
A/C Air-conditioning
AC Alternating Current – An electrical current where the polarity is constantly changing between positive and
negative
A/F Air / Fuel (A/F Ratio)
Analogue Signal An electrical signal that constantly varies in voltage within a given parameter
Barometric Pressure Barometric absolute pressure (atmospheric pressure)
CAN Controller Area Network – A type of serial data for communication between electronic devices.
Catalytic Converter
A muffler-shaped device fitted in the exhaust system, usually close to the engine. Through chemical reaction,
a catalytic converter converts harmful gases produced by the combustion process such as HC, CO, and NOx,
into environmentally safe water vapour, carbon dioxide, and nitrogen.
CKT Circuit
Closed Loop A fuel control mode of operation that uses the signal from the exhaust oxygen sensor(s), to control the air / fuel
ratio precisely at a 14.7 to 1 ratio. This allows maximum efficiency of the catalytic converter.
CO Carbon Monoxide. One of the gases produced by the engine combustion process.
DC Direct Current
Digital Signal An electrical signal that is either on or off.
DLC
Data Link Connector. Used at the assembly plant to evaluate the engine management system. For service, it
allows the use of Tech 2 in performing system checks.
DLC Data Stream An output from the ECM initiated by Tech 2 and transmitted via the Data Link Connector(DLC).
DMM (10 M Ω) Digital Multimeter. A multipurpose meter that has capability of measuring voltage, current flow and resistance.
A digital multimeter has an input impedance of 10 M Ω (megohms), which means they draw very little power
from the device under test, they are very accurate and will not damage delicate electronic components
Driver An electronic device, usually a power transistor, that operates as an electrical switch.
DTC
Diagnostic Trouble Code. If a fault occurs in the engine management system, the ECM may set a four digit
diagnostic trouble code (DTC) which represents the fault condition. Tech 2 is used to interface with the ECM
and access the DTC(s). The ECM may also operate the malfunction indicator lamp in the instrument cluster.
Duty Cycle The time, in percentage, that a circuit is on versus off.
ECT Sensor
Engine Coolant Temperature sensor. A device that provides a variable voltage to the ECM based on the
temperature of the engine coolant.
EEPROM Electrically Erasable Programmable Read Only Memory. A type of read only memory (ROM) that can be
electrically programmed, erased and reprogrammed using Tech 2. Also referred to as Flash Memory
EMI or Electrical
Noise An unwanted signal interfering with a required signal. A common example is the effect of high voltage power
lines on an AM radio.
Engine Braking A condition where the engine is used to slow the vehicle on closed throttle or low gear.
EPROM Erasable Programmable Read Only Memory. A type of Read Only Memory (ROM) that can be erased with
ultraviolet light and then reprogrammed.
ESD Electrostatic Discharge. The discharge of static electricity which has built up on an insulated material
EVAP
Evaporative emission control system. Used to prevent fuel vapours from the fuel tank from entering into the
atmosphere. The vapours are stored in a canister that contains an activated charcoal element. The fuel
vapours are purged from the canister into the manifold to be burned in the engine.
GM LAN General Motors Local Area Network - A type of serial data for communication between electronic devices.
Fuse
A thin metal strip which melts when excessive current flows through it, creating an open circuit and protecting
a circuit from damage.
HC Hydrocarbon. Result of unburned fuel produced by incomplete combustion.
Heavy Throttle Approximately 3/4 of accelerator pedal travel (75% throttle position)
IAT Sensor
Intake Air Temperature sensor. A device that provides a variable voltage to the ECM based on the
temperature of air entering the intake system.
Ideal Mixture The air / fuel ratio which provides the best performance, while maintaining maximum conversion of exhaust
emissions, typically 14.7 to 1 on spark ignition engines
IGN Ignition
Inputs Information from sensors (MAF, TP, etc.) and switches (A/C request, etc.) used by the ECM to determine how
to control its outputs.

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Engine Management – V6 – General Information Page 6C1-1–36

Intermittent
An electrical signal that occurs now and then; not continuously. In electrical circuits, refers to occasional open,
short, or ground in a circuit
Light Throttle Approximately 1/4 of accelerator pedal travel (25% throttle position)
Low
A voltage less than a specific threshold. Operates the same as a ground and may, or may not, be connected
to chassis ground.
MAF Sensor Mass Air Flow Sensor. A device that provides a variable voltage to the ECM based on the amount of air flow
entering in the intake system.
Medium Throttle Approximately 1/2 of accelerator pedal travel (50% throttle position)
N.C Normally Closed. Switch contacts that are closed when they are in the normal operating position
N.O Normally Open. Switch contacts that are normally open when in the normal operating position
NOx
Nitrogen Oxide. One of the pollutants found in spark ignition engine exhaust that is formed from normal
combustion and increases in severity with combustion temperature.
O2 Sensor Oxygen Sensor. A device located in the exhaust system that provides a variable voltage to the ECM based on
the oxygen content of exhaust gas.
May also include a heating circuit to provide faster initial warm-up (HO2 sensor).
OBD On Board Diagnostic
Open Loop ECM control of the fuel control system without the use of the oxygen sensor signal.
Output Functions that are controlled by the ECM, typically these can include solenoids and relays, etc.
ECM Engine Control Module. An electronic device which controls the engine management system.
ECU Electronic Control Unit. An electronic device which controls specific system functions
PCV
Positive Crankcase Ventilation. Method of reburning crankcase fumes rather than passing them directly into
the atmosphere
PIM Powertrain Interface Module – The PIM acts as a communication translator between the ECM and other on-
board controllers that use a different serial data protocol.
PM Permanent Magnet
PWM
Pulse Width Modulated. A digital signal turned on and off for a percentage of available cycle time. A signal that
is 30% on and 70% of would be termed a 30% on PWM signal.
Quad Driver A transistor in the ECM capable of operating four separate outputs. Outputs can be either on-off or pulse width
modulated.
RAM Random Access Memory. A microprocessor can write into or read from this memory as needed. This memory
is volatile and needs a constant power supply to be retained. If the power is lost or removed, RAM data is lost.
r.p.m. Revolutions Per Minute
Serial Data
Serial data is a series of rapidly changing voltage signals pulsed from high to low. These signals are typically
transmitted through a wire often referred to as the Serial Data Circuit.
SFI Sequential Fuel Injection. Method of injecting fuel into the engine one cylinder at a time in relation to the
engines firing order.
Solenoid An electromagnetic coil which creates a magnetic field when current is applied, causing a plunger or ball to
move.
Switch Device to opens and close a circuit, thereby controlling current flow.
Tech 2
Tech 2 is a peripheral device that aids in the diagnosis and repair of electronic systems such as engine
management, transmission control etc. Tech 2 connects to the vehicle’s Data Link Connector (DLC).
TP Sensor Throttle Position sensor. A device that provides a variable voltage to the ECM based on the position of the
throttle plate.
Vacuum – manifold Vacuum sourced downstream of the throttle plate.
Vacuum – ported Vacuum sourced upstream of the throttle plate.
VSS Vehicle Speed Sensor. A permanent magnet type device that provides a digital voltage to the ECM.
WOT Wide Open Throttle – Full travel of the accelerator pedal (100% throttle position).


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Engine Management – V6 – Diagnostics Page 6C1-2–4

1 General Information
1.1 Diagnostic System Check
The engine management diagnostic procedure is organised in a logical structure that begins with the Diagnostic System
Check. The Diagnostic System Check directs the diagnostic procedure to the logical steps necessary to diagnose an
engine driveability fault condition.
1.2 Diagnostic Trouble Code Tables
The Diagnostic System Check directs the diagnostic procedure to the appropriate diagnostic trouble code (DTC) tables
if there is a DTC currently stored in the engine control module (ECM).
The diagnostic tables locate a faulty circuit or component through a logic based on the process of elimination. These
diagnostic tables are developed with the following assumptions:
• the vehicle functioned correctly at the time of assembly,
• there are no multiple faults, and
• the problem currently exists.
Understanding and the correct use of the diagnostic tables are essential to reduce diagnostic time and to prevent
misdiagnosis.
Multiple DTC Fault Conditions
Some fault conditions trigger multiple component DTCs even if the fault condition exists only on a single component. If
there are multiple DTCs stored in the ECM, the service technician must view and record all DTCs logged.
The relationship between the logged DTCs can then be analysed to determine the source of the fault condition. Always
begin the diagnostic process with the DTC table of the fault condition that may trigger other DTCs to set.
The following fault conditions may trigger multiple DTCs:
• a fault in the serial data communication circuit,
• a system voltage that is too low may cause incorrect engine management system operation or engine
management component malfunction,
• a system voltage that is too high may damage the ECM and/or other engine management components,
• fault condition in the ECM read only memory (ROM) or random access memory (RAM),
• fault condition in the ECM internal circuitry or programming,
• improperly connected sensor or component wiring connector, or
• an electrical fault condition in the following shared ECM electrical circuits trigger DTCs on components or sensors
that share in the faulty shared circuit. Test the electrical circuit of the appropriate sensors or components to isolate
the fault condition. Refer to 3 W iring Diagrams and Connector Charts in this Section.
• 5 V Reference Circuit,
• Low Reference Circuit, or
• Ignition Control Voltage Circuit.
If there are no obvious faults to begin a multiple DTC fault condition diagnostic procedure, diagnose the DTCs in the
following order unless directed otherwise:
1 Always start with the lowest numbered component level DTCs such as:
• sensor DTCs,
• solenoid DTCs, or
• relay DTCs.
2 Then follow with system level DTCs such as:
• misfire DTCs,

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Engine Management – V6 – Diagnostics Page 6C1-2–12

3.2 ECM Connector End Views
Engine Control Module Connector E-60

Figure 6C1-2 – 5
Terminal / Pin Wire Colour Circuit
Description Function
E-60–1 BR KNK_RET2
Low Reference – Knock Sensor Bank 2
E-60–2 LG IN_PMP_2 B2S1 HO2S Input Pump Current (Bank 2 Sensor 1)
E-60–3 O IN_PMP_1 B1S1 HO2S Input Pump Current (Bank 1 Sensor 1)
E-60–4 O CMSFH_1 CMP Sensor Signal – Intake Bank 1
E-60–5 GR 5VDC2 5 Volt Reference – 6
E-60–6 Not Used
E-60–7 BR/R 5VGD2 Low Reference – Ground 2
E-60–8 V TPS_2 TP Sensor 2 Signal
E-60–9 G/W EST4 EST 4 Control
E-60–10 W ENG_SPD CKP Sensor High
E-60–11 Not Used
E-60–12 Not Used
E-60–13 Not Used
E-60–14 Not Used
E-60–15 BR ETC_POS TAC Motor Control (Positive)
E-60–16 V/W O2_HTR_1 B1S1 HO2S Heater Low Reference (Bank 1 Sensor 1)
E-60–17 GR KNK_RET1 Low Reference – Knock Sensor Bank 1
E-60–18 BR/W O2_RTN_2 B2S1 HO2S Low Signal (Bank 2 Sensor 1)
E-60–19 V HI_SIG_1 B1S1 HO2S High Signal (Bank 1 Sensor 1)
E-60–20 Not Used
E-60–21 GR CHRG_2 Generator Field Duty Cycle Signal (‘F’ Terminal)
E-60–22 Not Used
E-60–23 Y COL_TMP ECT Sensor Signal
E-60–24 Not Used
E-60–25 L/W EST6 EST 6 Control
E-60–26 O/W EST2 EST 2 Control

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E-60–27 Not Used
E-60–28 Not Used
E-60–29 Not
Used
E-60–30 Not Used
E-60–31 Y ETC_NEG TAC Motor Control (Negative)
E-60–32 L O2_HTR_2 B2S1 HO2S Heater Low Control (Bank 2 Sensor 1)
E-60–33 L KNK1 Knock Sensor 1 Signal (Bank 1)
E-60–34 V/W HI_SIG_2 B2S1 HO2S High Signal (Bank 2 Sensor 1)
E-60–35 V/W PMP_1 B1S1 HO2S Pump Current (Bank 1 Sensor 1)
E-60–36 Not Used
E-60–37 BR OIL_LVL Oil Level Switch Signal
E-60–38 G/W OIL_TMP Oil Temperature Sensor Signal
E-60–39 BR/T 5VGD3 Low Reference – Ground 3
E-60–40 GR/B OIL_PRESS Oil Pressure Sensor Signal
E-60–41 DG EST5 EST 5 Control
E-60–42 V EST1 EST 1 Control
E-60–43 O CHRG_1 Generator Turn On Signal (‘L’ Terminal)
E-60–44 Not Used
E-60–45 LB INJR_4 Fuel Injector 4 Control
E-60–46 P/L INJR_3 Fuel Injector 3 Control
E-60–47 BR/W INJR_5 Fuel Injector 5 Control
E-60–48 G/W CNPUR EVAP Canister Purge Solenoid Control
E-60–49 GR/B RET5 CKP Sensor Shield Return
E-60–50 LB KNK2 Knock Sensor 2 Signal (Bank 2)
E-60–51 W PMP_2 B2S1 HO2S Pump Current (Bank 2 Sensor 1)
E-60–52 BR/G O2_RTN_1 B1S1 HO2S Low Signal (Bank 1 Sensor 1)
E-60–53 Not Used
E-60–54 GR 5VDC2 5 Volt Reference – 2
E-60–55 G TPS-1 TP Sensor 1 Signal
E-60–56 LG MAP MAP Sensor Signal
E-60–57 GR 5VDC5 5 Volt Reference – 5
E-60–58 LB EST3 EST 3 Control
E-60–59 B 5VGD6 CKP Sensor Low – Ground 6
E-60–60 Not Used
E-60–61 Not Used
E-60–62 LG INJR_2 Fuel Injector 2 Control
E-60–63 BR/L INJR_1 Fuel Injector 1 Control
E-60–64 Y/B INJR_6 Fuel Injector 6 Control

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