2007 ISUZU KB P190 catalytic converter

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 6C1-2–102

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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Engine Management – V6 – Diagnostics Page 6C1-2–121

Step Action Yes No
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 ignition coil control 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.
7.23 DTC P0420 or P0430
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0420 Catalyst System Low Efficiency Bank 1
• DTC P0430 Catalyst System Low Efficiency Bank 2
Circuit Description
To maintain a reasonably low emission level of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen
(NOx) a 3-way catalytic converter (TW C) is used. The catalyst within the converter promotes a chemical reaction that
oxidizes the HC and CO present in the exhaust gas. This reaction converts the gases into harmless water vapour and
carbon dioxide. The catalyst also reduces the NOx, converting the NOx into nitrogen. The engine control module (ECM)
monitors this process using the post catalyst heated oxygen sensor (HO2S) signal. The post-catalyst HO2S located in
the exhaust stream after the TW C, produces an output signal that indicates the oxygen storage capacity of the catalyst.
The oxygen storage capacity (OSC) determines the ability of the catalyst to convert the exhaust emissions effectively. If
the catalyst is functioning correctly, the post-catalyst HO2S signal will be far less active than the signal produced by the
pre-catalyst HO2S.
To determine OSC, the ECM commands a rich air / fuel mixture until all oxygen is removed from the catalyst. The ECM
then commands a lean air / fuel mixture and monitors the rear heated oxygen sensors to calculate the oxygen storage
capacity. The catalyst is operated in this mode until one of the following conditions occur:
• The oxygen stored in the catalyst exceeds a calibrated threshold, which is determined from the rear HO2S signal.
• The rear HO2S indicates the catalyst to be completely saturated with oxygen, which is determined from the rear
HO2S signal.
If the ECM detects the average OSC is less than a threshold, this DTC sets. This indicates that the TW C oxygen
storage capacity is below a threshold considered acceptable.
Conditions for Running the DTC
• Before the ECM can report, the following DTCs must run and pass:
DTC P0420 or P0430 failed, DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0053,
P0056, P0057, P0058, P0059, P0101, P0102, P0103, P0121, P0122, P0123, P0130, P0131, P0132, P0133,
P0135, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157, P0158, P0159,
P0160, P0161, P0221, P0222, P0223, P0335, P0336, P0338, P167A, P167B, P2096, P2097, P2098, P2099,
P2195, P2196, P2197, P2198, P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271,
P2272, P2273, P2297, P2298, P2626, and P2629.
• The following DTCs are not set:
DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0053, P0056, P0057, P0058,
P0059, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0125, P0130, P0131,
P0132, P0133, P0135, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157,

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Engine Management – V6 – Diagnostics Page 6C1-2–122

P0158, P0159, P0160, P0161, P0221, P0222, P0223, P0300, P0301-P0306, P0443, P0458, P0459, P0496,
P167A, P167B, P2096, P2097, P2098, P2099, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128,
P2138, P2176, P2177, P2178, P2179, P2180, P2187, P2188, P2189, P2190, P2195, P2196, P2197, P2198,
P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271, P2272, P2273, P2297, P2298,
P2626, and P2629.
• The engine speed is 1,040 – 3,000 rpm.
• The air flow into the engine is between 7.0 – 16.0 g/s and not changing more than 3.0 g/s
• The engine intake air temperature (IAT) at engine start-up is more than –30° C.
• The engine is operating for more than 7 minutes.
• The engine is operating in Closed Loop.
• The calculated TW C temperature is between 500 – 750° C and steady.
• The above conditions exist for approximately 17 minutes.
• DTCs P0420 and P0430 run once a drive cycle. The ECM will attempt to run this diagnostic up to three times a
drive cycle.
Conditions for Setting the DTC
The ECM determines that the catalyst efficiency has degraded below a calibrated threshold for more than 4 seconds.
Action Taken When the DTC Sets
• The control module activates 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 DTC
The EVAP Purge Solenoid Valve Control Circuit DTCs are Type B DTCs. Refer to 1.4 Diagnostic Trouble Codes in
this Section, for action taken when a Type B DTC sets and conditions for clearing Type B DTCs.
P0420 or P0430 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 in this Section
2 Are any other DTCs set? Go to the
appropriate DTC
Table in this Section Go to Step 3
3 1 Inspect for the following conditions:
• The catalytic converter is an original equipment part.
• Inspect the exhaust system for leaks, damage, loose or
missing hardware in the area from the converter to the
heated oxygen sensor 2.
• The HO2S 2 is secure and the wiring is not damaged or
contacting the exhaust.
Did you find and correct the condition? Go to Step 5 Go to Step 4

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Engine Management – V6 – Diagnostics Page 6C1-2–123

Step Action Yes No
4 NOTE
Before replacing the 3-way catalytic converter (TW C),
correct any conditions that may have damaged the
converter.
1 Replace the catalytic converter. Refer to the appropriate procedure in 6F Exhaust System – V6.
Did you complete the replacement? Go to Step 5 —
5 1 Using Tech 2, clear the DTC/s.
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 EVAP purge solenoid valve control circuit DTCs fail
this ignition cycle? Go to Step 2 Go to Step 6
6 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
7.24 DTC P0443, P0458 or P0459
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0443 – Evaporative Emission Control System Purge Solenoid Circuit Malfunction
• DTC P0458 – Evaporative Emission Control System Purge Solenoid Circuit Low Voltage
• DTC P0459 – Evaporative Emission Control System Purge Solenoid Circuit High Voltage
Circuit Description
The Engine control relay applies ignition positive battery voltage to the evaporative emission (EVAP) purge solenoid.
Using a device called a driver, the ECM applies a pulse width modulated (PW M) ground to the EVAP solenoid control
circuit to purge the fuel vapour from the EVAP canister into the intake manifold.
The driver has a feedback circuit that is pulled-up to a voltage. The ECM monitors the driver feedback circuit to
determine if the control circuit is open, shorted to ground or shorted to a positive voltage.
An EVAP purge solenoid valve control circuit DTC sets if the ECM detects the voltage on the EVAP solenoid control
circuit outside the predetermined range when the solenoid is commanded off.
Conditions for Running the DTC
DTC P0443 and P0458
Runs continuously once the following conditions are met:
• The engine speed is greater than 80 rpm
• The ignition voltage is 10.0 – 16.0 V.
• The ECM has commanded the EVAP Purge Solenoid Valve on and off at least once during the ignition cycle.
DTC P0459
Runs continuously once the following conditions are met:

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Engine Management – V6 – Diagnostics Page 6C1-2–239

B1/B2 S1 O2 Sensor 1 (Bank 1 or Bank 2 Sensor 1): This parameter displays the lambda output from the HO2S to the
ECM. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0 indicates a lean exhaust.
B1/B2 S2 O2 Sensor 2 (Bank 1 or Bank 2 Sensor 2): This parameter displays the mV output from the HO2S to the
ECM. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich exhaust.
B1/B2 S1 O2 Sensor Heater (Bank 1 or Bank 2 Sensor 1): This parameter displays the resistance of the sensing
element within the ECM. The front sensors are normally regulated to 80 ohms.
B1/B2 S1/S2 O2 Sensor Heater Circuit Status (Bank 1 or Bank 2 Sensor 1 or Sensor 2): The parameter displays
‘Fault’ if the oxygen sensor heater control circuit is open, shorted to ground, or shorted to voltage. The parameter
displays ‘Undefined’ until the circuit has been commanded ON.
Barometric Pressure: This parameter displays the barometric pressure in kPa. The ECM uses the barometric pressure
for fuel control to compensate for altitude differences.
Barometric Pressure: This parameter displays the barometric pressure voltage. The control module uses the
barometric pressure for fuel control to compensate for altitude differences.
Brake Lamp Switch: This parameter displays the status of the brake lamp switch. W hen the brake pedal is pressed the
switch contacts close causing the vehicles brake lamps to illuminate.
Brake Switch Signal Status: This parameter displays the position of the torque converter clutch (TCC) brake pedal
switch input to the ECM.
Calculated ECT – Closed Loop Fuel Control (Engine Coolant Temperature): This parameter displays the modelled
temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air
temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined
amount of time, a DTC will set.
Calculated ECT – Thermostat Diagnosis (Engine Coolant Temperature): This parameter displays the modelled
temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air
temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined
amount of time, a DTC will set.
Calculated Pedal Position: This parameter displays the angle of the accelerator pedal position (APP) as calculated by
the ECM, using the signals from the APP sensors, as a percentage of throttle opening.
Calculated Throttle Position: This parameter displays the percentage of throttle opening, based on the two TP sensor
inputs to the ECM.
Catalyst Protection Mode: This parameter displays if the control module is commanding catalytic converter protection
or not.
Catalyst Temperature (Bank 1 or Bank 2): This parameter displays the catalytic converter temperature as calculated
by the control module.
Clutch Pedal Switch: This parameter displays the state of the clutch pedal as determined by the ECM from the clutch
start switch position.
Clutch Pedal Switch: This parameter displays the state of the clutch pedal as determined by the ECM from the clutch
pedal switch.
Commanded Exhaust Camshaft Position (Bank 1 or Bank 2): This parameter displays the exhaust camshaft position
in percent of range as commanded by the control module.
Commanded Exhaust Camshaft Position (Bank 1 or Bank 2): This parameter displays the exhaust camshaft position
in crankshaft degrees, as commanded by the ECM.
Commanded Intake Camshaft Position (Bank 1 or Bank 2): This parameter displays the intake camshaft position in
crankshaft degrees, as commanded by the ECM.
Commanded B1/B2 S1 O2 Sensor Heater (Bank 1 or Bank 2 Sensor 1): This parameter displays the state of the
oxygen sensor heater control circuit, as a percentage.
Commanded B1/B2 S1 O2 Sensor Value (Bank 1 or Bank 2 Sensor 1): This parameter displays the lambda output
from the HO2S to the ECM. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0 indicates a lean
exhaust.
Coolant Temperature: This parameter displays the temperature of the engine coolant based on input to the control
module from the engine coolant temperature (ECT) sensor.
Crank Request: This parameter displays whether the ignition switch has been cycled to the crank position, requesting
the ECM to activate the starter relay.
Cruise Control Active: This parameter displays the status of the cruise control system as determined by the ECM.

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