2007 ISUZU KB P190 ECO mode

Engine Management – V6 – Diagnostics Page 6C1-2–78

Step Action Yes No
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 ECT sensor 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.
7.9 DTC P0121, P0122, P0123, P0221,
P0222,or P0223
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0121 – Throttle Position Sensor 1 Circuit Range / Performance
• DTC P0122 – Throttle Position Sensor 1 Circuit Low Voltage
• DTC P0123 – Throttle Position Sensor 1 Circuit High Voltage
• DTC P0221 – Throttle Position Sensor 2 Circuit Range / Performance
• DTC P0222 – Throttle Position Sensor 2 Circuit Low Voltage
• DTC P0223 – Throttle Position Sensor 2 Circuit High Voltage
Circuit Description
The ECM applies 5 V to the throttle position (TP) sensor 1 through the 5 V reference circuit and the ground through the
low reference circuit. TP sensor 1 and TP sensor 2 share common 5 V reference circuit and low reference circuit.
The TP sensor 1 and TP sensor 2 have individual signal circuits with opposite functionality. These signal circuits provide
the ECM with a signal voltage that is proportional to the throttle plate movement.
• The TP sensor 1 signal voltage is less than 1 V when the throttle plate is in closed position, which increases to
greater than 4 V when the throttle plate is moved to wide-open throttle.
• The TP sensor 2 signal voltage is greater than 4 V when the throttle plate is in closed position, which decreases to
less than 1 V when the throttle plate is moved to wide-open throttle.
The ECM monitors and compares the TP sensor 1 signal voltage to the TP sensor signal voltage 2. In addition, the ECM
compares the TP sensor signal to the MAF sensor signal to determine a calculated TP sensor signal.
A TP sensor DTC sets if the ECM detects a fault condition in the TP sensor signal output.
Conditions for Running the DTC
DTC P0121 runs continuously once the following conditions are met:
• The ignition voltage is greater than 7 V.
• The TP sensor 1 signal voltage is 0.17 – 4.6 V.
DTC P0122, P0123, P0222 and P0223 runs continuously once the following conditions are met:
• The ignition voltage is greater than 7 V.
• The ignition is switched on.
DTC P0221 runs continuously once the following conditions are met:
• The battery voltage is greater than 7 V.

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Engine Management – V6 – Diagnostics Page 6C1-2–80

Test Description
The following number refers to the step number in the diagnostic table:
6 Measures the integrity of the TP sensor low reference circuit. Removal of the ECM Fuse 29 enables the ECM to power down completely prior to the test procedure.
DTC P0121, P0122, P0123, P0221, P0222 or P0223 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 Quickly depress the accelerator pedal to wide-open throttle then release pedal. Repeat this procedure several times or operate
the vehicle within the conditions for running the DTC.
4 Using Tech 2, select the DTC display function.
Does DTC P0121, P0122, P0123, P0221, P0222 or P0223 fail this
ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 1 Disconnect the throttle actuator wiring connector.
2 Switch on the ignition with the engine not running.
3 Using a digital multimeter, measure the voltage between the TP sensor 5 V reference circuit and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 4 Go to Step 7
4 1 Connect a 3 A fused jumper wire between the TP sensor 5 V
reference circuit and the TP sensor 1 signal circuit.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the TP sensor 1 voltage parameter.
Does Tech 2 display 4.8 – 5.2 V?
Go to Step 5 Go to Step 8
5 1 Connect a 3 A fused jumper wire between the TP sensor 5 V
reference circuit and the TP sensor 2 signal circuit.
2 Using Tech 2, observe the TP sensor 2 voltage parameter.
Does Tech 2 display 4.8 – 5.2 V?
Go to Step 6 Go to Step 9
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance between the TP 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 the test.
Does the multimeter display 5 Ω? Go to Step 11 Go to Step 10

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ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–81

Step Action Yes No
7
NOTE
TP sensor 1 share the 5 V reference circuit with TP sensor
2. A fault condition in the TP sensor 5 V reference circuit
may trigger DTCs on both sensors.
Test the TP sensor 5 V reference 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 13 Go to Step 12
8 Test the TP sensor 1 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 13 Go to Step 12
9 Test the TP sensor 2 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 13 Go to Step 12
10 Test the TP sensor low reference circuit for a high resistance or an
open circuit 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 13 Go to Step 12
11 Replace the throttle body assembly. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 13 —
12 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 13 —
13 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 TP Sensor Circuit DTCs fail this ignition cycle? Go to Step 2 Go to Step 14
14 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.
7.10 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
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0130 – O2 Sensor Circuit Malfunction (Bank 1, Sensor 1)

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Engine Management – V6 – Diagnostics Page 6C1-2–84

• The calculated exhaust temperature is 250ºC – 800ºC.
• The engine coolant temperature is less than 40ºC at start-up and greater than 60ºC when the ignition was turned
off last ignition cycle.
• The fuel tank level is greater than 25 percent.
DTC P0138 and P0158
Run continuously once the following conditions are met:
• The engine is operating for longer than two minutes.
• The ignition voltage is 10.0 – 16.0 V.
• The HO2S is at operating temperature.
• The calculated exhaust temperature is 250ºC – 800ºC.
DTC P0140 and P0160
Run continuously once the following conditions are met for longer than 90 seconds:
• The engine is operating.
• The ignition voltage is 10.0 – 16.0 V.
• The calculated exhaust temperature is 250º C – 800º C.
DTC P0141 and P0161
Run continuously once the following conditions are met:
• DTCs P0036, P0037, P0038, P0056, P0057, and P0058 ran and passed.
• DTCs P0137, P0138, P0140, P0157, P0158, or P0160 are not set.
• The engine is operating.
• The ECM internal sensing element resistance is valid.
• The fuel system is not in decel fuel shut-off.
• The intake air temperature is greater than -7ºC.
• If the engine is operating and the ignition is turned off, the engine must be off for at least 5 minutes for this DTC to
run.
• The ignition voltage is 10.0 – 16.0 V.
• The calculated exhaust temperature is 360ºC – 500ºC.
DTC P2243 and P2247
Run continuously once the following conditions are met:
• DTCs P0030, P0031, P0032, P0050, P0051 and P0052 ran and passed.
• The ECM internal sensing element resistance is greater than 570 Ω.
• The HO2S is at operating temperature.
DTC P2270 and P2272
Run continuously once the following conditions are met:
• DTCs P0036, P0037, P0038, P0056, P0057, P0058, P0137, P0138, P0140, P0141, P0157, P0158, P0160, P0161,
P0342, P0343, P0443, P0458 and P0459 ran and passed.
• The engine is running.
• The HO2S 2 are at operating temperature for longer than 10 seconds.
• The long term fuel control is enabled.

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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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