2007 ISUZU KB P190 ESP

Engine Management – V6 – Diagnostics Page 6C1-2–35

Checks Actions
Fuel System
• Check the fuel system for the following fault conditions. Refer to 6C Fuel System
– V6.
− restricted fuel filter,
− incorrect fuel pressure, and
− contaminated fuel.
• Check the operation of the fuel injectors. Refer to 6C1-3 Engine Management –
V6 – Service Operations.
• Perform the fuel injector balance test, refer to 6.3 Fuel Injector Balance
Test in this Section.
• Check the items that cause an engine to run rich.
Ignition System
• Inspect for moisture or corrosion around the spark plug and ignition coil area.
• Test the ignition coil voltage output. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Remove and inspect the spark plugs. Refer to 6C1-3 Engine Management –V6 –
Service Operations.
NOTE
If the spark plugs are fouled, determine the cause of the fouling before
replacing the spark plugs. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Check for loose ignition coil grounds.
Engine Mechanical
• Parasitic load on the engine such as the following:
• automatic transmission fault condition, or
• a belt driven accessory fault condition.
• Check for the following engine fault conditions. Refer to 6A1 Engine Mechanical –
V6.
• low compression, or
• worn valve train components.
When all diagnosis and repairs are completed, check the system for correct operation.
5.13 Surges / Chuggles
Description
W ith the accelerator pedal in a steady position, the vehicle speeds up and slows down or the engine power fluctuates.
Checks Actions
Preliminary Perform the preliminary checks. Refer to 4.3 Preliminary Checks in this Section.
Sensor / System
• Using Tech 2, check the heated oxygen sensor (HO2s) operating parameters.
The HO2s should respond quickly to different throttle positions.
• Test the resistance of the crankshaft position (CKP) sensor. The CKP sensor
resistance must be 700 – 1,200 Ω at all temperatures.

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Engine Management – V6 – Diagnostics Page 6C1-2–51

DTC Description Diagnostic Table
P0058 O2 Sensor Heater Circuit High Voltage (Bank 2, Sensor 2) 7.3 DTC P0030, P0031, P0032, P0036,
P0037, P0038, P0050, P0051, P0052,
P0056, P0057 or P0058
P0059 O2 Sensor Heater Resistance Range / Performance (Bank 2, Sensor 1) 7.5 DTC P0053 or P0059
P0101 Mass Air Flow Sensor Circuit Range / Performance 7.6 DTC P0101, P0102 or P0103
P0102 Mass Air Flow Sensor Voltage Low
7.6 DTC P0101, P0102 or P0103
P0103 Mass Air Flow Sensor Voltage High 7.6 DTC P0101, P0102 or P0103
P0112 Intake Air Temperature Sensor Circuit Low Voltage 7.7 DTC P0112 or P0113
P0113 Intake Air Temperature Sensor Circuit High Voltage 7.7 DTC P0112 or P0113
P0116 Engine Coolant Temperature Sensor Circuit Range /
Performance 7.8 DTC P0116, P0117, P0118, P0125 or
P1258
P0117 Engine Coolant Temperature Sensor Circuit Low Voltage 7.8 DTC P0116, P0117, P0118, P0125 or P1258
P0118 Engine Coolant Temperature Sensor Circuit High Voltage 7.8 DTC P0116, P0117, P0118, P0125 or P1258
P0121 Throttle Position Sensor 1 Circuit Range / Performance 7.9 DTC P0121, P0122, P0123, P0221, P0222,or P0223
P0122 Throttle Position Sensor 1 Circuit Low Voltage 7.9 DTC P0121, P0122, P0123, P0221,
P0222,or P0223
P0123 Throttle Position Sensor 1 Circuit High Voltage 7.9 DTC P0121, P0122, P0123, P0221,
P0222,or P0223
P0125 Insufficient Engine Coolant Temperature For Closed Loop Fuel Control 7.8 DTC P0116, P0117, P0118, P0125 or
P1258
P0130 O2 Sensor Circuit Malfunction (Bank 1, Sensor 1) 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
P0131 O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1) 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
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1) 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
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) 7.11 DTC P0133 or P0153
P0135 O2 Sensor Heater Circuit Range / Performance (Bank 1, Sensor 1) 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
P0137 O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2) 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

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Engine Management – V6 – Diagnostics Page 6C1-2–52

DTC Description Diagnostic Table
P0138 O2 Sensor Circuit High Voltage (Bank 1, Sensor 2) 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
P0139 O2 Sensor Slow Response (Bank1 Sensor 2) 7.12 DTC P0139 or P0159
P0140 O2 Sensor Circuit No Activity Detected (Bank 1
Sensor 2) 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
P0141 O2 Sensor Heater Circuit Range / Performance (Bank 1, Sensor 2) 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
P0150 O2 Sensor Circuit Malfunction (Bank 2, Sensor 1) 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
P0151 O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1) 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
P0152 O2 Sensor Circuit High Voltage (Bank 2, Sensor 1) 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
P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1) 7.11 DTC P0133 or P0153
P0155 O2 Sensor Heater Circuit Range / Performance (Bank 2, Sensor 1) 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
P0157 O2 Sensor Circuit Low Voltage (Bank 2, Sensor 2) 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
P0158 O2 Sensor Circuit High Voltage (Bank 2, Sensor 2) 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
P0159 O2 Sensor Slow Response (Bank1 Sensor 2) 7.12 DTC P0139 or P0159
P0160 O2 Sensor Circuit No Activity Detected (Bank 2, Sensor 2) 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
P0161 O2 Sensor Heater Circuit Range / Performance (Bank 2, Sensor 2) 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

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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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ISUZU KB P190 2007

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 6C1-2–91

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 6C1-2–102

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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Engine Management – V6 – Diagnostics Page 6C1-2–105

Circuit Description
The engine control module (ECM) uses information from the crankshaft position (CKP) sensor and the camshaft position
(CMP) sensor 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
3-way catalytic converter damage. The malfunction indicator lamp (MIL) will flash ON and OFF when the conditions for
catalytic converter damage are preset. DTCs P0301 – P0306 correspond to cylinders 1 to 6. If the ECM is able to
determine that a specific cylinder is misfiring, the DTC for that cylinder 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 with the transmission in neutral.
• The delivered torque signal is between 10 – 30 percent with the transmission in drive.
• The intake air temperature (IAT) is more than –30° C.
• The engine run time is more than 45 seconds.
• The fuel level is more than 12 percent.
• The torque management is not active.
• DTCs P0301, P0302, P0303, P0304, P0305, and P0306 run 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 single cylinder misfire rate sufficient to cause
emissions levels to exceed mandated standards.
• The condition 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. Check for the
following possible sources:
− Tyre or wheel out of round or balance
− Variable thickness brake rotor or drum
− Drive shaft not balanced
− Certain rough road conditions

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