2007 ISUZU KB P190 Electrical

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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ISUZU KB P190 2007

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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ISUZU KB P190 2007

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 6C1-2–89

• 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 6C1-2–93

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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Engine Management – V6 – Diagnostics Page 6C1-2–96

• 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.
Test Description
The following numbers refer to the step numbers in the diagnostic table:
5 Test signal circuit of the EOT sensor. This circuit should display a voltage within the specified range.
6 Measures the integrity of the EOT sensor low reference circuit. Removal of the Fuse 29 enables the ECM to power down completely prior to the test procedure.
DTC P0196, P0197 or P0198 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 Test the engine cooling system for correct operation. Refer to 6B1
Engine Cooling – V6.
W as any fault found and rectified? Go to Step 11 Go to Step 3
3 Inspect the engine oil condition. Refer to 6A1 Engine Mechanical –
V6.
W as any fault found and rectified? Go to Step 11 Go to Step 4
4 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0196, P0197 or P0198 fail this ignition cycle? Go to Step 5 Refer to Additional
Information in this DTC
5 1 Switch off the ignition.
2 Disconnect the EOT sensor wiring connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage between the EOT sensor signal circuit and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 6 Go to Step 7
6 1 Switch off the ignition.
2 Remove ECM / TCM Fuse 29 from the engine compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance between the EOT 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 this test.
Does the multimeter display 5 Ω? Go to Step 9 Go to Step 8
7 Test EOT sensor 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 11 Go to Step 10

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