ISUZU KB P190 2007 Workshop Repair Manual

Engine Management – V6 – Diagnostics Page 6C1-2–93

4 1 Ignition OFF.
2 Disconnect the affected heated oxygen sensor (HO2S) 2
3 Connect a 3 Amp fused jumper wire between the HO2S high signal circuit, on the engine harness
side connector, and a good ground.
4 Ignition ON, engine OFF.
5 Use Tech 2 to observe the affected HO2S 2 parameter
Is the voltage less than the specified value? 25 mV
Go to Step 5 Go to Step 7
5 1 Remove the jumper wire from the previous step.
2 Connect a 3 Amp fused jumper wire between the HO2S high signal circuit and the HO2S low
signal circuit, on the engine harness side
connector.
3 Use Tech 2 to observe the HO2S 2 parameter.
Is the voltage less than the specified value? 25 mV
Go to Step 6 Go to Step 8
6 1 Remove the jumper wire from the previous step.
2 Measure the resistance of the following circuits with a DMM:
• The HO2S heater low control circuit.
• The ignition voltage circuit Refer to 8A
Electrical-Body and Chassis.
Is the resistance of either circuit more than the
specified value? 5
Ω
Go to Step 12 Go to Step 9
7 1 Test the HO2S high signal circuit for an open or
high resistance. Refer to 8A Electrical-Body and
Chassis.
Did you find and correct the condition? —
Go to Step 15 Go to Step 11
8 1 Test the HO2S low signal circuit for an open or
high resistance. Refer to 8A Electrical-Body and
Chassis.
Did you find and correct the condition? —
Go to Step 15 Go to Step 11

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Engine Management – V6 – Diagnostics Page 6C1-2–94

9 1 The HO2S is detecting a rich or lean exhaust
condition or may be contaminated. Inspect for
one of the following conditions:
• HO2S connector water intrusion.
• A silicon-contaminated HO2S.
• Fuel-contaminated engine oil – refer to 6.5
Alcohol / Contaminants in Fuel
Diagnosis.
• Rich fuel injectors.
• Lean fuel injectors. Refer to 6C Fuel
System – V6
• An exhaust leak between the HO2S and
the engine. Refer to 6F Exhaust System –
V6.
• Vacuum leaks.
• Fuel contamination. W ater, even in small
amounts, can be delivered to the fuel
injectors, causing a lean exhaust to be
indicated. Excessive alcohol in the fuel can
also cause this condition. Refer to 6.5
Alcohol / Contaminants in Fuel
Diagnosis in this Section.
• An inaccurate mass air flow (MAF) sensor.
2 Repair any of the above or similar engine conditions, as necessary.
Did you find and correct the condition? —
Go to Step 15 Go to Step 10
10 1 Test for intermittent and poor connections at the
HO2S. Refer to 8A Electrical-Body and Chassis.
Did you find and correct the condition? —
Go to Step 15 Go to Step 13
11 1 Test for intermittent and poor connections at the
engine control module (ECM). Refer to 6C1-3
Engine Management – V6 – Service Operations.
Did you find and correct the condition? —
Go to Step 15 Go to Step 14
12 1 Repair the circuit with high resistance. Refer to
8A Electrical-Body and Chassis.
Did you complete the repair? —
Go to Step 15 —
13 1 Replace the affected HO2S. Refer to 6C1-3
Engine Management – V6 – Service Operations.
Did you complete the replacement? —
Go to Step 15 —
14 1 Replace the ECM. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
Did you complete the replacement? —
Go to Step 15 —
15 1 Use Tech 2 to clear the DTCs.
2 Turn OFF the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the Conditions for Running the DTC. You may also operate the
vehicle within the conditions that you observed
from the Freeze Frame / Failure Records.
Did the DTC fail this ignition? —
Go to Step 2 Go to Step 16

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Engine Management – V6 – Diagnostics Page 6C1-2–95

16 1 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? —
Go to the
appropriate DTC Table in this Section System OK
When all diagnosis and repairs are completed, clear all DTCs and verify correct operation
7.13 DTC P0196, P0197 or P0198
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0196 – Engine Oil Temperature Sensor Range / Performance
• DTC P0197 – Engine Oil Temperature Voltage Low
• DTC P0198 – Engine Oil Temperature Voltage High
Circuit Description
The ECM applies a positive 5 V reference voltage to the engine oil temperature (EOT) sensor through the 5 V reference
circuit and the ground through the low reference circuit.
The EOT sensor is a variable resistor that measures the temperature of the engine oil. This sensor provides signal
voltage to the ECM that is proportional to the oil temperature off the engine.
The ECM monitors and compares the EOT sensor signal voltage against a specified range. An EOT sensor circuit DTC
sets if the ECM detects the EOT sensor signal voltage is outside the specified range.
Conditions for Running the DTC
DTC P0196, P0197 and P0198 run continuously when the engine is running.
Conditions for Setting the DTC
DTC P0196
The ECM detects the engine oil temperature sensor is not within 100 °C of the modelled temperature
NOTE
The modelled temperature is the temperature
that the ECM expects to see given current engine
operating conditions.
DTC P0197
The ECM detects the engine oil temperature is less than -35 °C for longer than 3 seconds.
DTC P0198
The ECM detects the engine oil temperature is greater than 170 °C for longer than 3 seconds.
Conditions for Clearing DTC
The EOT sensor circuit DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type C DTC sets and conditions for clearing Type C DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the EOT sensor operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.

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Engine Management – V6 – Diagnostics Page 6C1-2–96

• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
5 Test signal circuit of the EOT sensor. This circuit should display a voltage within the specified range.
6 Measures the integrity of the EOT sensor low reference circuit. Removal of the Fuse 29 enables the ECM to power down completely prior to the test procedure.
DTC P0196, P0197 or P0198 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 Test the engine cooling system for correct operation. Refer to 6B1
Engine Cooling – V6.
W as any fault found and rectified? Go to Step 11 Go to Step 3
3 Inspect the engine oil condition. Refer to 6A1 Engine Mechanical –
V6.
W as any fault found and rectified? Go to Step 11 Go to Step 4
4 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0196, P0197 or P0198 fail this ignition cycle? Go to Step 5 Refer to Additional
Information in this DTC
5 1 Switch off the ignition.
2 Disconnect the EOT sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage between the EOT sensor signal circuit and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 6 Go to Step 7
6 1 Switch off the ignition.
2 Remove ECM / TCM Fuse 29 from the engine compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance between the EOT sensor low reference circuit and the ECM housing.
NOTE
Install the ECM Fuse 29 to the engine compartment fuse
and relay panel assembly after completing this test.
Does the multimeter display 5 Ω? Go to Step 9 Go to Step 8
7 Test EOT sensor signal circuit for a high resistance, open circuit,
short to ground or short to voltage fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 11 Go to Step 10

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Engine Management – V6 – Diagnostics Page 6C1-2–97

Step Action Yes
No
8 Test the EOT sensor low reference circuit for a high resistance and
open circuit fault condition. Refer to 8A Electrical - Body and Chassis
for information on electrical fault diagnosis.
NOTE
The EOT sensor shares the low reference circuit with
other sensors. A fault condition in the low reference circuit
may trigger DTCs on sensors that share this circuit. Refer
to 3 W iring Diagrams and Connector Charts in this
Section, to assist diagnosis.
W as any fault found and rectified? Go to Step 11 Go to Step 10
9 Replace the EOT sensor. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the conditions for the engine oil pressure sensor circuit
DTCs fail this ignition cycle? Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.14 DTC P0201, P0202, P0203, P0204, P0205,
P0206, P0261, P0262, P0264, P0265,
P0267, P0268, P0270, P0271, P0273,
P0274, P0276 or P0277
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0201 – Injector 1 Control Circuit Malfunction
• DTC P0202 – Injector 2 Control Circuit Malfunction
• DTC P0203 – Injector 3 Control Circuit Malfunction
• DTC P0204 – Injector 4 Control Circuit Malfunction
• DTC P0205 – Injector 5 Control Circuit Malfunction
• DTC P0206 – Injector 6 Control Circuit Malfunction
• DTC P0261 – Injector 1 Control Circuit Low Voltage
• DTC P0262 – Injector 1 Control Circuit High Voltage
• DTC P0264 – Injector 2 Control Circuit Low Voltage
• DTC P0265 – Injector 2 Control Circuit High Voltage
• DTC P0267 – Injector 3 Control Circuit Low Voltage

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Engine Management – V6 – Diagnostics Page 6C1-2–98

• DTC P0268 – Injector 3 Control Circuit High Voltage
• DTC P0270 – Injector 4 Control Circuit Low Voltage
• DTC P0271 – Injector 4 Control Circuit High Voltage
• DTC P0273 – Injector 5 Control Circuit Low Voltage
• DTC P0274 – Injector 5 Control Circuit High Voltage
• DTC P0276 – Injector 6 Control Circuit Low Voltage
• DTC P0277 – Injector 6 Control Circuit High Voltage
Circuit Description
The engine control relay applies ignition positive voltage to the fuel injector ignition circuit. The ECM applies a pulse
width modulated (PW M) ground to the injector control circuit through a device within the ECM called a driver to control
each fuel injector on time.
The driver has a feedback circuit that is pulled-up when the voltage is approximately 3.3 V. The ECM monitors the driver
feedback circuit to determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
A fuel injector control circuit DTC sets if the ECM detects a fault condition in a fuel injector control circuit.
Conditions for Running the DTC
Run continuously once the following conditions are met:
• the battery voltage is 10.0 – 16.0 V, and
• engine speed is greater than 80 rpm
Conditions for Setting the DTC
DTC P0201,P0202, P0203, P0204, P0205 or P0206
The ECM detects an open circuit fault condition in a fuel injector circuit.
DTC P0261, P0264, P0267, P0270, P0273 and P0276
The ECM detects a short to ground fault condition in the control circuit a fuel injector.
DTC P0262, P0265, P0268, P0271, P0274 and P0277
The ECM detects a short to voltage fault condition in the control circuit of a fuel injector.
Conditions for Clearing the DTC
The fuel injector control circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for
action taken when Type B DTC sets and conditions for clearing Type B DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the fuel injector operation.
• Using Tech 2, observe the appropriate fuel injector status parameter while wriggle testing related harness and
connectors. Tech 2 reading will change from Ok to Fault if there is an intermittent fault condition in the harness or
connector being tested.
• Perform the fuel injector coil test to help isolate an intermittent condition. Refer to 6.2 Fuel Injector Coil
Test in this Section.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.

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Engine Management – V6 – Diagnostics Page 6C1-2–99

Test Description
The following numbers refer to the step numbers in the diagnostic table:
3 Determines if there is a fault condition in the ignition voltage supply circuit. The fuel injectors for each bank of the engine are fused separately. If all DTCs for a single bank are set, there may be a fault in one of the ignition supply
circuits.
5 Verifies the ECM is sending control voltage to the fuel injector.
6 Tests if the feed back voltage circuit within the ECM is providing the correct voltage.
DTC P0201 to P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273,
P0274, P0276 and P0277 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Start the engine.
3 Using Tech 2, select the DTC display function.
Does DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261,
P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274,
P0276 or P0277 set? Go to Step 3 Refer to Additional
Information in this DTC
3 1 Disconnect the fuel injector interconnect harness connector.
Refer to 6C1-3 Engine Management – V6 – Service Operations.
2 Switch on the ignition with the engine not running.
3 Connect a test lamp between the ignition voltage circuit of the appropriate fuel injector, ECM side of the interconnect
connector, and the ECM housing.
Does the test lamp illuminate? Go to Step 4 Go to Step 5
4 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage between the appropriate fuel injector control circuit, ECM side of the
interconnect connector, and the ECM housing.
Does the multimeter display 2.6 – 4.6 mV? Go to Step 7 Go to Step 6
5 Repair the open circuit or short to ground fault condition in the ignition
voltage circuit of the appropriate fuel injector. Refer to 8A Electrical -
Body and Chassis for information on electrical wiring repair
procedures.
W as the repair completed? Go to Step 10 —
6 Test the control circuit of the appropriate fuel injector, between the
interconnect connector and the ECM, for a high resistance, open
circuit, short to ground or short to voltage fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 10 Go to Step 9

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Engine Management – V6 – Diagnostics Page 6C1-2–100

Step Action Yes No
7 1 Remove the upper intake manifold. Refer to 6A1-Engine
Mechanical – V6.
2 Test the control circuit and the ignition voltage circuit of the appropriate fuel injector, between the interconnect connector
and the appropriate fuel injector connector, for a high
resistance, open circuit, short to ground or short to voltage fault
condition. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 10 Go to Step 8
8 Replace the appropriate fuel injector. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 10 —
9 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 10 —
10 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the fuel injector control circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 11
11 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.15 DTC P0219
DTC Descriptor
This diagnostic procedure supports DTC P0219 – Engine Overspeed Condition.
Circuit Description
The ECM continually monitors the engines operating environment. A engine over-speed condition DTC sets if the ECM
detects an engine speed in excess of 7200 RPM.
NOTE
An over-speed condition will occur when a low
gear on a manual transmission vehicle has been
selected whilst the vehicle is travelling at high
road speed. This DTC will not set if the engine is
free-revved as the ECM will limit engine speed.
Conditions for Running the DTC
DTC P0219 runs continuously when the following conditions are met:
• The vehicle is fitted with a manual transmission
• The engine is running.
• The ignition voltage is between 10.0 – 16.0 V.

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Engine Management – V6 – Diagnostics Page 6C1-2–101

Conditions for Setting the DTC
The ECM detects an engine speed in excess of 7200 RPM for 1 second or longer.
Conditions for Clearing the DTC
The engine over-speed DTC is a Type C DTC. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when Type C DTCs set and conditions for clearing Type C DTCs.
Additional Information
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
DTC P0219 Diagnostic Table
Step Action Yes No
1 Has the diagnostic system check been performed?
Go to Step 2 Refer to
4.4 Diagnostic System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
5 Using Tech 2, select the DTC display function.
Does DTC P0219 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 4 —
4 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P0219 fail this ignition cycle? Go to Step 2 Go to Step 5
5 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.16 DTC P0300
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0300 Engine Misfire Detected.
Circuit Description
The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position
(CMP) sensors to determine when an engine misfire is occurring. By monitoring variations in the crankshaft rotation
speed for each cylinder, the ECM is able to detect individual misfire events. A misfire rate that is high enough can cause

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Engine Management – V6 – Diagnostics Page 6C1-2–102

3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for
catalytic converter damage are present. DTCs P0301 through P0306 correspond to cylinders 1 through 6. If the ECM is
able to determine that a specific cylinder is misfiring, the DTC for that cylinder will set. If the misfire rate is sufficient to
cause emission levels to exceed a predetermined value, this DTC sets.
Conditions for Running the DTC
• DTCs P0121, P0122, P0123, P0221, P0222, P0223, P0335, P0336, or P0338 are not set.
• The engine speed is between 400 – 7,000 rpm and steady.
• The delivered torque signal is more than 10 percent at idle.
• The delivered torque signal is between 9 – 30 percent with the transmission in drive.
• The intake air temperature (IAT) is more than –30° C.
• The fuel level is more than 12 percent.
• The torque management is not active.
• DTC P0300 runs continuously when the above conditions exist for at least 1,000 engine revolutions.
Conditions for Setting the DTC
• The ECM detects a crankshaft rotation speed variation indicating a misfire rate sufficient to cause emissions levels
to exceed mandated standards.
• The condition above exists for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates the MIL on the second ignition cycle that the diagnostic runs and fails.
• The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic
fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the
second consecutive ignition cycle, the control module records the operating conditions at the time of the failure.
The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The ECM turns OFF the malfunction indicator lamp (MIL) after four consecutive ignition cycles that the diagnostic
runs and does not fail.
• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission
related diagnostic.
• Use Tech 2 to clear the MIL and the DTC.
Additional Information
• A misfire DTC could be caused by an excessive vibration from sources other than the engine. Inspect for the
following possible sources:
− A tyre or wheel that is out of round or out of balance
− Variable thickness brake rotors
− An unbalanced drive shaft
− Certain rough road conditions
− A damaged accessory drive component or belt
• A misfire DTC could be caused by a camshaft actuator stuck in the full advance or retard position.
• For an intermittent condition, refer to 5.2 Intermittent Fault Conditions in this Section.

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