sensor ISUZU KB P190 2007 Workshop Repair Manual

Engine Management – V6 – Diagnostics Page 6C1-2–85

• The MAF sensor is greater than 10 g/s.
DTC P2297 and P2298
Condition 1
Run continuously once the following conditions are met:
• DTCs P0130 and P0150 ran and passed.
• The HO2S 1 are at operating temperature.
• The desired HO2S 1 signal is less than 1.6 lambda.
• The internal ECM HO2S 1 signal voltage is less than 4.81 V.
• The fuel injectors are enabled.
Condition 2
Run continuously once a decel fuel cut-off has occurred 11 times with successful adjustments
Conditions for Setting the DTC
DTC P0130 and P0150
The ECM detects the HO2S signal voltage is out of range.
DTC P0131 and P0151
The ECM internal HO2S voltage is less than the specified threshold.
DTC P0132 and P0152
The ECM internal HO2S voltage is less than the specified threshold.
DTC P0135 and P0155
Condition 1
The ECM internal HO2S sensing element resistance is less than the specified threshold for longer than 15 seconds.
Condition 2
The ECM detects the calculated HO2S temperature is greater than a predetermined threshold.
DTC P0137 and P0157
The ECM detects the HO2S signal voltage is less than 60 mV.
DTC P0138 and P0158
The ECM detects the HO2S signal voltage is greater than 1050 mV.
DTC P0140 and P0160
The ECM detects one of the following conditions:
• The HO2S signal voltage is 400 – 500 mV for longer than 5 minutes, or
• the internal resistance of the HO2S is greater than 40,000 Ω when the calculated exhaust temperature is greater
than 600ºC.
DTC P0141 and P0161
The ECM detects the HO2S internal resistance is not within the expected range for longer than 6 seconds.

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Engine Management – V6 – Diagnostics Page 6C1-2–86

DTC P2243 and P2247
The ECM detects the internal HO2S signal voltage is not 0.2 – 4.7 V.
DTC P2270 and P2272
W hen the ECM detects the HO2S 2 is less than 650 mV for 100 seconds, the ECM enriches the fuel mixture up to 30
percent for 10 seconds. This DTC sets if the ECM detects the HO2S 2 is still less than 650 mV.
DTC P2271 and P2273
W hen the ECM detects the HO2S 2 is greater than 650 mV for 100 seconds, the ECM leans the fuel mixture up to -7
percent for 10 seconds. If this signal voltage is still greater than 650 mV, the ECM tests the HO2S at the next decel fuel
cut-off. This DTC sets if the ECM detects the HO2S 2 signal voltage is greater than 200 mV after 4 seconds in decel fuel
cu-off mode.
DTC P2297 and P2298
The ECM detects the internal HO2S 1 signal voltage is greater than 3.7 V for longer than 10 seconds.
Conditions for Clearing the DTC
The HO2S reference 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 HO2S system operation.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• The HO2S must be tightened correctly. A loose HO2S will trigger these DTCs.
• A fault condition in the fuel delivery system, air intake system or exhaust system may trigger these DTCs.
• 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 P0130 to P0132, P0135 to P0138, P0140, P0141, P0150 to P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270 to P2273, P2297 or P2298 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 Allow the engine to reach the normal operating temperature.
4 Increase the engine speed to 2,000 rpm for 10 seconds or operate the vehicle within the conditions for setting the DTC.
5 Using Tech 2, select the DTC display function.
Does DTC P0130, P0131, P0132, P0135, P0137, P0138, P0140,
P0141, P0150, P0151, P0152, P0155, P0160, P0161, P2243, P2247,
P2270, P2271, P2272, P2273, P2297 or P2298 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Are DTCs relating to the heater circuit of the O2 sensor, also set?
(e.g. P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051,
P0052, P0056, P0057 or P0058) Go to the
appropriate DTC
Table in this Section Go to Step 4

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Engine Management – V6 – Diagnostics Page 6C1-2–87

Step Action Yes No
4 1 Disconnect the appropriate HO2S wiring connector.
2 Switch on the ignition with the engine not running.
3 Using a digital multimeter, measure the voltage between the HO2S reference signal circuit and low reference circuit.
Does the multimeter display 350 – 550 mV? Go to Step 7 Go to Step 5
5 1 Test the reference signal circuit of the HO2S 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 6
6 1 Test the low reference circuit of the HO2S 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
7 1 Test or inspect for the following conditions that may cause the
HO2S to detect an incorrect air / fuel mixture:
− lean or rich fuel injector fuel delivery,
− restricted air intake system,
− contaminated fuel,
− low fuel line pressure,
− exhaust leak near the HO2S, and
− leak in the crankcase or vacuum line.
W as any fault found and rectified? Go to Step 10 Go to Step 8
8 1 Replace the appropriate HO2S. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 10 —
9 1 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 HO2S reference circuit DTC fail this ignition cycle? Go to Step 2 Go to Step 11
11 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, check the system for correct operation.
7.11 DTC P0133 or P0153
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0133 – HO2S Circuit Slow Response – Bank 1 Sensor 1

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Engine Management – V6 – Diagnostics Page 6C1-2–88

• DTC P0153 – HO2S Circuit Slow Response – Bank 2 Sensor 1
Circuit Description
The wide band heated oxygen sensor (HO2S) measures the amount of oxygen in the exhaust system and provides
more information than the switching style HO2S. The wide band sensor consists of an oxygen sensing cell, an oxygen
pumping cell, and a heater.
The exhaust gas sample passes through a diffusion gap between the sensing cell and the pumping cell. The engine
control module (ECM) supplies a voltage to the HO2S and uses this voltage as a reference to the amount of oxygen in
the exhaust system. An electronic circuit within the ECM controls the pump current through the oxygen pumping cell to
maintain a constant voltage in the oxygen sensing cell. The ECM monitors the voltage variation in the sensing cell and
attempts to keep the voltage constant by increasing or decreasing the amount of current flow, or oxygen ion flow, to the
pumping cell.
By measuring the amount of current required to maintain the voltage in the sensing cell, the ECM can determine the
concentration of oxygen in the exhaust. The HO2S voltage is displayed as a lambda value. A lambda value of 1 is equal
to a stoichiometric air fuel ratio of 14.7:1. Under normal operating conditions, the lambda value will remain around 1.
W hen the fuel system is lean, the oxygen level will be high and the lambda signal will be high or more than 1. W hen the
fuel system is rich, the oxygen level will be low, and the lambda signal will be low or less than 1. The ECM uses this
information to maintain the correct air / fuel ratio.
Conditions for Running the DTC
• Before the ECM can report DTC P0133 or P0153 failed, DTCs P0121, P0122, P0123, P0221, P0222, P0223,
P0336, P0338, P2237, and P2240 must run and pass.
• DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0053, P0059, P0130, P0131, P0132, P0135, P0150, P0151,
P0151, P0152, P0155, P0442, P0443, P0446, P0455, P0458, P0459, P0496, P167A, P167B, P2096, P2097,
P2098, P2099, P2231, P2234, P2243, P2247, P2251, P2254, P2297, P2298, P2626, and P2629 are not set.
• The HO2S is at operating temperature.
• The HO2S is between 0.94 – 1.06 lambda.
• The engine speed is between 1,480 – 2,040 rpm.
• The volumetric efficiency is between 16.5 – 38.3 percent.
• The change in volumetric efficiency is less than 3 percent.
• The evaporative emission (EVAP) purge is not active, or the ECM determines the EVAP hydrocarbon (HC)
concentration is less than a predetermined amount when EVAP purge is active.
• The long term fuel trim correction is active.
• DTCs P0133 and P0153 run continuously once the above conditions are met for 10 minutes.
Conditions for Setting the DTC
• The ECM has determined that the dynamic value of the affected HO2S is less than a predetermined threshold.
• The above condition is met for more than 4 seconds.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive 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.

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Engine Management – V6 – Diagnostics Page 6C1-2–89

• 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/DTC.
Additional Information
• Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a
component harness connector.
• The lower connector of the ECM is connector A43-X1 and the upper connector of the ECM is connector A43-X2.
Refer to 3 W iring Diagrams and Connector Charts in this Section.
• The front wide band sensors do not toggle or switch like a switching HO2S. The front HO2S signals will be
relatively stable for an idling engine.
• 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.
• The following table illustrates the typical voltages for the HO2S circuits:
HO2S Voltages
Conditions: • Ignition ON, Engine OFF
• HO2S Disconnected
HO2S Circuit Voltage
Heater Control 4.6 – 5.0 V
Heater Supply Voltage B+
Reference Voltage 2.6 – 3.1 V
Low Reference 2.2 – 2.7 V
Pump Current Less than 0.5 A
Input Pump Current Less than 0.5 A
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2 This step determines if the condition exists.
4 This step determines if the fuel system is contaminated.
DTC P0133 or P0153 Diagnostic Table
Step Action Yes No
1
Has the Diagnostic System Check been completed? Go to Step 2 Refer to
4.4 Diagnostic System Check

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Engine Management – V6 – Diagnostics Page 6C1-2–90

Step Action Yes No
2 NOTE
• DTC P0133 is for bank 1 sensor 1 and DTC P0153 is
for bank 2 sensor 1.
• DTC P0132 causes DTC P0153 to set. If DTC P0132
is set with DTC P0153, refer to 7.10 DTC
P0130, P0131, P0132, P0135, P0137, P0138, P0140,
P0141, P0150 P0151, P0152, P0155, P0157, P0158,
P0160, P0161, P2243, P2247, P2270, P2271, P2272,
P2273, P2297 or P2298 in this Section.
• Inspect the heated oxygen sensor (HO2S) for being
secure before proceeding with this DTC. A sensor that
is loose could cause this DTC to set.
1 Start engine and allow to reach operating temperature.
2 Observe the diagnostic trouble code (DTC) information with Tech 2.
Did DTC P0133 and / or DTC P0153 fail this ignition cycle? Go to Step 4 Go to Step 3
3 1 Observe the Freeze Frame / Failure Records for this DTC.
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 4 Go to Additional
Information in this DTC
4 Did DTC P0133 and DTC P0153 fail this ignition cycle? Go to Step 7 Go to Step 5
5 1 Inspect for an exhaust leak near the HO2S. Refer to 6F Exhaust
System – V6. After you inspect the exhaust system, return to
this diagnostic.
Did you find and correct the condition? Go to Step 8 Go to Step 6
6 1 Inspect or test for the following conditions:
• Inspect that the HO2S is securely installed.
• Inspect for corrosion on the HO2S terminals.
• Inspect the terminal tension at the HO2S and at the
engine control module (ECM). Refer to 8A Electrical-Body
and Chassis.
• Inspect the HO2S wiring for damage.
Did you find and correct the condition? Go to Step 8 Go to Step 7

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Engine Management – V6 – Diagnostics Page 6C1-2–91

Step Action Yes No
7 NOTE
If both DTCs are set, determine and correct the cause of
the contamination before replacing a sensor.
1 Inspect for the following conditions:
• Fuel contamination – refer to 6.5 Alcohol / Contaminants
in Fuel Diagnosis in this Section.
• The correct RTV sealant.
• Engine oil consumption – refer to 6A1 Engine Mechanical
– V6.
• Engine coolant consumption – refer to 6B1 Engine Cooling
– V6.
2 Replace the HO2S. Refer to 6C1-3 Engine Management – V6 – Service Operations.
Did you complete the replacement? Go to Step 8 —
8 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 9
9 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
7.12 DTC P0139 or P0159
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0139 – O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
• DTC P0159 – O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
Circuit Description
The post catalytic converter heated oxygen sensor (HO2S) produces a voltage that varies between 100 – 900 mV under
normal operating conditions. The engine control module (ECM) produces a bias voltage on the HO2S signal circuit of
420 – -480 mV. The reference ground for the sensor is provided through the ECM.
The ECM monitors the signal voltage to determine if the exhaust is lean or rich. The oxygen sensor voltage is high when
the exhaust is rich, and low when the exhaust is lean. The ECM constantly monitors the HO2S signal during the Closed
Loop operation. If the ECM detects that the decel fuel cut-off rich-to-lean transition time is too long, DTC P0139 will set
for bank 1 sensor 2, or DTC P0159 will set for bank 2 sensor 2.
Conditions for Running the DTC
• DTCs P0021, P0024, P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058,
P0101, P0102, P0103, P0106, P0107, P0108, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128,
P0131, P0132, P0135, P0137, P0138, P0139, P0140, P0141, P0151, P0152, P0155, P0157, P0158, P0159,
P0160, P0161, P0201-P0208, P0221, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270,
P0271, P0273, P0274, P0276, P0277, P0279, P0280, P0282, P0283, P0300, P0301-P0308, P0335, P0336,

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Engine Management – V6 – Diagnostics Page 6C1-2–92

P0340, P0341, P0345, P0346, P0351-P0358, P0365, P0366, P0390, P0391, P0442, P0443, P0446, P0449,
P0453, P0454, P0455, P0458, P0459, and P0496 are not set.
• The ECT Sensor parameter is more than 66° C.
• The Vehicle Speed Sensor parameter is between 5 – 180 km/h.
• The calculated catalytic converter temperature is more than 520° C.
• DTC P0139 or P0159 runs continuously once the above conditions are met.
Conditions for Setting the DTC
• The ECM detects that the decel fuel cut-off and rich-to-lean transition time has exceeded 1 second.
Action Taken When the DTC Sets
• The ECM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the
diagnostic runs and fails.
• The ECM 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 ECM 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 three 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.
DTC P0139 or P0159 Diagnostic Table
Step Action Value(s) Yes No
1
Has the Diagnostic System Check been completed? —
Go to Step 2 Refer to
4.4 Diagnostic System Check
2 1 Start and run the engine until normal operating
temperature is reached.
2 Quickly cycle the throttle from closed throttle to wide open throttle (W OT) 3 times within
5 seconds while observing the HO2S Bank 1
Sensor 2 or HO2S Bank 2 Sensor 2 voltage
parameter with Tech 2.
Does the voltage react immediately when performing
the above action? —
Go to Step 3 Go to Step 4
3 1 Observe the Freeze Frame / Failure Records for
this DTC.
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 4 Go to 5.2
Intermittent Fault Conditions in this Section.

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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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