Infiniti G35 (V35). Manual - part 354

DTC P0137, P0157 HO2S2

EC-297

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Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

 Without CONSULT-II

1.

Start engine and warm it up to the normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

4.

Let engine idle for 1 minute.

5.

Set voltmeter probes between ECM terminal 74 [HO2S2 (B1) signal] or 55 [HO2S2 (B2) signal] and
ground.

6.

Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.68V at least once during this
procedure.
If the voltage is above 0.68V at step 6, step 7 is not neces-
sary.

7.

Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position (A/T), 4th gear position (M/T).
The voltage should be below 0.18V at least once during this
procedure.

8.

If NG, replace heated oxygen sensor 2.

CAUTION:

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Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.

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Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Removal and Installation

NBS000X1

HEATED OXYGEN SENSOR 2

Refer to 

EM-25, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

PBIB1607E

EC-298

DTC P0138, P0158 HO2S2

DTC P0138, P0158 HO2S2

PFP:226A0

Component Description

NBS001NY

The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.

CONSULT-II Reference Value in Data Monitor Mode

NBS000QH

Specification data are reference values.

On Board Diagnosis Logic

NBS001NZ

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the air fuel ratio (A/
F) sensor 1. The oxygen storage capacity of the three way catalyst 1 causes the longer switching time.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the voltage is unusually high during the various driving con-
dition such as fuel-cut.

MALFUNCTION B
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the minimum voltage of sensor is sufficiently low during the
various driving condition such as fuel-cut.

SEF327R

MONITOR ITEM

CONDITION

SPECIFICATION

HO2S2 (B1)
HO2S2 (B2)

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Revving engine from idle to 3,000 rpm quickly after the following condi-
tions are met.

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Engine: After warming up

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Keeping the engine speed between 3,500 rpm and 4,000 rpm for 1 minute 
and idle for 1 minute under no load.

0 - 0.3V 

←→

 Approx. 0.6 - 

1.0V

HO2S2 MNTR(B1)
HO2S2 MNTR(B2)

LEAN 

←→

 RICH

PBIB1848E

PBIB2376E

DTC P0138, P0158 HO2S2

EC-299

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DTC Confirmation Procedure

NBS000QJ

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

 WITH CONSULT-II

1.

Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.

2.

Start engine and warm it up to the normal operating tempera-
ture.

3.

Turn ignition switch OFF and wait at least 10 seconds.

4.

Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.

5.

Let engine idle for 2 minutes.

6.

If 1st trip DTC is detected, go to 

EC-303, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

Overall Function Check

NBS001O0

PROCEDURE FOR MALFUNCTION B

Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.

 With GST

1.

Start engine and warm it up to the normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

4.

Let engine idle for 1 minute.

5.

Set voltmeter probes between ECM terminal 55 [HO2S2 (B2) signal] or 74 [HO2S2 (B1) signal] and
ground.

6.

Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0.18V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.

7.

Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.

8.

If NG, go to 

EC-305, "PROCEDURE FOR MALFUNCTION B"

 .

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0138
0138
(Bank 1)

Heated oxygen sensor 
2 circuit high voltage

A)

An excessively high voltage from the sen-
sor is sent to ECM.

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Harness or connectors
(The sensor circuit is open or shorted)

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Heated oxygen sensor 2

P0158
0158
(Bank 2)

B)

The minimum voltage from the sensor is 
not reached to the specified voltage.

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Harness or connectors
(The sensor circuit is open or shorted)

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Heated oxygen sensor 2

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Fuel pressure

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Fuel injector

SEF174Y

PBIB1607E

EC-300

DTC P0138, P0158 HO2S2

Wiring Diagram

NBS000QK

BANK 1

TBWM1615E