2007 ISUZU KB P190 ECO mode

Engine Management – V6 – Diagnostics Page 6C1-2–193

5 1 Start the engine.
NOTE
Additional DTCs will set when the MAF
sensor is disconnected.
2 Disconnect the mass air flow (MAF) sensor harness connector while the engine is operating.
3 Observe the Short Term FT parameter for bank 1 and bank 2 with Tech 2.
4 Reconnect the MAF sensor after completing this step.
Does the Short Term FT parameter for both banks of
the engine change more than the specified value with
the MAF sensor disconnected? 20%
Go to 7.6
DTC
P0101, P0102 or P0103 in this Section Go to Step 6
6 1 Inspect for the following conditions:
− Vacuum hoses for splits, kinks, and proper
connections.
− The throttle body and the intake manifold
for vacuum leaks.
− The crankcase ventilation valve and system
for leaks.
− Air intake system after the MAF sensor for
vacuum leaks.
− Contaminated fuel – Refer to 6.5 Alcohol /
Contaminants in Fuel Diagnosis in this
Section.
− Lean injectors – Refer to 6.2 Fuel
Injector Coil Test in this Section.
− The ECM grounds for being clean, tight,
and in the correct locations
− A high engine oil level condition. A high
engine oil level causes oil residue to form
on the MAF sensor, causing a lean
indication. The MAF sensor does not need
to be replaced.
− An engine mechanical condition – refer to
6A1 – Engine Mechanical V6.
Did you find and correct the condition? —
Go to Step 8 Refer to Additional
Information and Test Descriptionin this DTC
7 1 Inspect for the following conditions:
− Vacuum leaks that only affect one bank of
the engine – For example, the intake
manifold, the injector O-rings.
− Lean injectors – refer to 6.2 Fuel
Injector Coil Test in this Section
− Exhaust leaks, missing or loose exhaust
hardware.
− The heated oxygen sensor (HO2S) is
installed securely and the electrical
connector is not contacting the exhaust
system.
− An engine mechanical condition – 6A1 –
Engine Mechanical V6.
Did you find and correct the condition? —
Go to Step 8 Refer to Additional
Information in this DTC.


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Engine Management – V6 – Diagnostics Page 6C1-2–194

8 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.
Did DTC P2179 or P2189 fail this ignition cycle? —
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
7.54 DTC P2188 or P2190
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P2188 Fuel Trim System Rich at Idle Bank 1
• DTC P2190 Fuel Trim System Rich at Idle Bank 2
Circuit Description
The engine control module (ECM) controls the air / fuel metering system to provide the best possible combination of
driveability, fuel economy, and emission control. Fuel delivery is controlled differently during Open and Closed Loop.
During Open Loop, the ECM determines fuel delivery based on sensor signals without heated oxygen sensor (HO2S)
input. During Closed Loop, the HO2S inputs are added and used by the ECM to calculate short and long term fuel trim
fuel delivery adjustments. If the HO2S indicate a lean condition, fuel trim values will be above 0 percent. If the O2S
indicate a rich condition, fuel trim values will be below 0 percent. Short term fuel trim values change rapidly in response
to the HO2S signals. Long term fuel trim makes coarse adjustments to maintain an air / fuel ratio of 14.7:1. If the ECM
detects an excessively rich condition, this DTC sets.
Conditions for Running the DTC
• Before the ECM can report DTC P2188 or P2190 failed, DTCs P0101, P0121, P0122, P0123, P0133, P0153,
P0221, P0222, P0223, P0336, P0338, P0443, P0458, P0459, P0461, P0462, P0463, P2066, P2067, and P2068
must run and pass.
• The fuel system is in Closed Loop.
• The long fuel trim is active.
• The engine coolant temperature (ECT) is more than 60°C (140°F).
• The evaporative emission (EVAP) canister purge solenoid valve is not enabled.
• The intake air temperature (IAT) is less than 60°C (140°F).
• The fuel level is more than 11.6 percent.
• The amount of air flow into the engine is more than 7 000 grams.
• DTC P2188 and P2190 runs continuously once the above conditions are met for at least 300 seconds
Conditions for Setting the DTC
• The Total Fuel Trim Avg. is less than –40 percent.
• The LT FT Idle / Decel is less than -7 percent.
• The condition exists for 4 seconds.

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Engine Management – V6 – Diagnostics Page 6C1-2–195

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 MIL/DTC
• The control module 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 fuel delivery condition causes this DTC to set. Thoroughly inspect all items that cause a rich condition.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• 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 numbers below refer to the step numbers on the diagnostic table.
2 This step determines whether the fault is present.
4 If DTC P2188 and P2190 set at the same time, then both banks of the engine are operating rich. Inspect items that would cause both banks to operate rich.
5 Disconnecting the mass air flow (MAF) sensor determines if the MAF sensor signal is skewed. If the Short Term FT parameter changes more than the specified value, there is a condition with the MAF sensor. A MAF sensor
condition can cause this DTC without setting a MAF DTC. If there is a MAF sensor condition, the MAF sensor
parameters will appear to be within range.
DTC P2188 or P2190 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 in this Section
2 NOTE
If any DTCs are set, except P2188 and
P2190, refer to those DTCs before
proceeding with this diagnostic.
1 Idle the engine at the normal operating temperature.
2 Check that the fuel system is in Closed Loop.
3 Observe the Total Fuel Trim Avg. parameter for bank 1 and / or bank 2 with Tech 2.
Is the Total Fuel Trim Avg. less than the specified
value? –40%
Go to Step 3 Go to Step 4

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Engine Management – V6 – Diagnostics Page 6C1-2–196

3 1 Observe the Freeze Frame and / or the Failure
Records data for this DTC.
2 Turn the ignition OFF 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 and / or the Failure
Records data.
Does the DTC fail this ignition cycle? —
Go to Step 4 Go to Additional
Information in this DTC.
4 Are both banks of the engine operating rich? —
Go to Step 5 Go to Step
5 1 Start the engine.
NOTE
Additional DTCs will set with the mass air
flow (MAF) sensor disconnected.
2 Disconnect the MAF sensor harness connector while the engine is operating.
3 Observe the Short Term FT parameter for Bank 1 and Bank 2 with Tech 2.
4 Connect the MAF sensor after completing this step.
Does the Short Term FT parameter for both banks of
the engine change more than the specified value with
the MAF sensor disconnected? 20%
Go to 7.6
DTC
P0101, P0102 or P0103 Go to Step 5
6 1 Inspect for the following conditions:
− A collapsed air intake duct
− A restricted air filter element
− Inspect the MAF sensor for foreign
objects.
− Excessive fuel in the crankcase – Change
the oil as necessary.
− Contaminated fuel. Refer to 6.5 Alcohol /
Contaminants in Fuel Diagnosisin this
Section.
− The engine control grounds for being
clean, tight, and in the correct locations
− An engine mechanical condition – refer to
6A1 – Engine Mechanical V6.
Did you find and correct the condition? —
Go to Step 8 Go to 6C Fuel
System – V6
7 1 Inspect for the following conditions:
− Rich injectors – Refer to 6.2 Fuel
Injector Coil Test in this Section
− Restricted exhaust system – Refer to 6F
Exhaust System – V6.
− An engine mechanical condition – refer to
6A1 – Engine Mechanical V6.
Did you find and correct the condition? —
Go to Step Go to Additional
Information in this DTC

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Engine Management – V6 – Diagnostics Page 6C1-2–197

8 1 Turn OFF the ignition for 30 seconds.
2 Using Tech 2, clear the DTCs and reset the fuel trim system.
3 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 DTC P2188 and / or P2190 fail this ignition cycle? —
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
7.55 DTC P2195 or P2197
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P2195 – B1S1 O2 Sensor – System Too Lean (Bank 1 Sensor 1)
• DTC P2197 – B2S1 O2 Sensor – System Too Lean (Bank 2 Sensor 1)
Circuit Description
The wide band heated oxygen sensor 1 (HO2S1) measures the amount of oxygen in the exhaust system and provides
more information than the switching style HO2S2. 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, maintaining 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 P2195 or P2197 failed, DTCs P0137, P0138, P0140, P0141, P0157, P0158,
P0160, P0161, P2270, P2271, P2272, and P2273 must run and pass.
• The front and rear heated oxygen sensors are at operating temperature.
• The rear HO2S voltage signal is more than 850 mV.
• The front HO2S is more than 1.08 lambda.
• The Loop Status for both the front and rear sensors is Closed Loop.
• DTCs P2195 and P2197 run continuously once the above conditions are met.
Conditions for Setting the DTC
Condition 1
• The ECM detects that the front HO2S is operating too lean while the rear HO2S is operating too rich and the ECM
detects that the fuel trim is at maximum control,
OR

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Engine Management – V6 – Diagnostics Page 6C1-2–198

• The rear fuel trim, long and short term, is more than a threshold.
• This DTC sets after the air flow coming into the engine accumulates to more than 200 grams and the above
conditions are met for more than 4 seconds.
Condition 2
• The ECM detects that the rear HO2S is operating too rich while the ECM is commanding a lean air / fuel mixture.
• This DTC sets after the air flow coming into the engine accumulates to more than 800 grams and the above
condition is met for more than 4 seconds.
Action Taken When the DTC Sets
• The ECM activates 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
control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
• The control module 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 HO2S fault condition may cause this DTC to set. Thoroughly inspect all items that could cause a lean condition.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Since a 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 numbers below refer to the step numbers on the diagnostic table.
2 This step determines if a condition exists.
5 This step is testing for a rear HO2S sensor circuit condition. A circuit condition sets this DTC.
8 This step is testing for an intermittent circuit condition. Thoroughly inspect the HO2S circuits for an intermittent circuit condition.
9 This step is testing for an intermittent circuit condition. Thoroughly inspect the HO2S circuits for an intermittent circuit condition.
DTC P2195 or P2197 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 in this Section

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Engine Management – V6 – Diagnostics Page 6C1-2–199

2 1 Allow the engine to reach operating temperature.
2 Operate the vehicle within the parameters specified in Conditions for Running the DTC.
3 Observe the diagnostic trouble code (DTC) information, using Tech 2.
Did DTC P2195 or DTC P2197 fail this ignition? —
Go to Step 4 Go to Step 3
3 1 Observe the Freeze Frame and/or the Failure
records data for this DTC.
2 Turn the ignition OFF 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 and / or the Failure
records data.
Does the DTC fail this ignition cycle? —
Go to Step 4 Refer to Additional
Information in this DTC.
4 Is DTC P0041, P0137, P0138, P0140, P0157, P0158,
or P0160 also set? —
Go to the
appropriate DTC Table in this Section Go to Step 5
5 1 Operate the engine above 1,200 RPM for
30 seconds.
2 Observe the appropriate rear HO2S voltage, using Tech 2.
Is the voltage more than the specified value? 60 mV
Go to Step 8 Go to Step 6
6 1 Ignition OFF.
2 Disconnect the appropriate rear heated oxygen sensor (HO2S).
3 Ignition ON, engine OFF.
4 Observe the appropriate rear HO2S voltage parameter with Tech 2.
Is the voltage within the specified range? 350 – 550 mV
Go to Step 12 Go to Step 7
7 1 Test the appropriate rear HO2S signal circuit for
a short to ground. Refer to 8A Electrical - Body
and Chassis.
Did you find and correct the condition? —
Go to Step 19 Go to Step 14
8 1 Shake the related HO2S harnesses for the front
sensor between the HO2S harness connector
and the engine control module (ECM) while
monitoring the appropriate HO2S lambda
parameter.
Does the HO2S parameter change abruptly while
moving the related harnesses? —
Go to Step 15 Go to Step 9
9 1 Shake the related HO2S harnesses for the rear
sensor between the HO2S harness connector
and the ECM while monitoring the appropriate
HO2S voltage parameter.
Does the HO2S parameter change abruptly while
moving the related harnesses? —
Go to Step 15 Go to Step 10

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Engine Management – V6 – Diagnostics Page 6C1-2–201

18 1 Replace the ECM. Refer to Engine Control
Module (ECM) Remove, Reinstall and ECM
Reset in 6C1- Engine Management – V6 Service
Operations.
Did you complete the replacement? —
Go to Step 19 —
19 1 Clear the DTCs, using Tech 2.
2 Turn OFF the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P2195 or P2197 fail this ignition cycle? —
Go to Step 2 Go to Step 20
20 1 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTC? —
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
7.56 P2196 or P2198
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P2196 – B1S1 O2 Sensor – System Too Rich (Bank 1 Sensor 1)
• DTC P2198 – B2S1 O2 Sensor – System Too Rich (Bank 2 Sensor 1)
Circuit Description
The wide band heated oxygen sensor 1 (HO2S1) measures the amount of oxygen in the exhaust system and provides
more information than the switching style HO2S2. 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, maintaining 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 P2196 or P2198 failed, DTCs P0137, P0138, P0140, P0141, P0157, P0158,
P0160, P0161, P2270, P2271, P2272, and P2273 must run and pass.
• The front and rear heated oxygen sensors are at operating temperature.
• The rear HO2S voltage signal is more than 150 mV.
• The front HO2S is more than 0.92 lambda.
• The Loop Status for both the front and rear sensors is Closed Loop.
• DTCs P2196 and P2198 run continuously once the above conditions are met.

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