Isuzu KB P190. Manual — part 842

Engine Management – V6 – Diagnostics

Page 6C1-2–90

Step Action

Yes

No

2

N O T E

• 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

Engine Management – V6 – Diagnostics

Page 6C1-2–91

Step Action

Yes

No

7

N O T E

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,

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 (WOT) 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.

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