Nissan Pathfinder (2006 year). Manual - part 177

DTC P0137, P0157 HO2S2

EC-275

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2006 Pathfinder

3. 

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect heated oxygen sensor 2 harness connector.

3.

Disconnect ECM harness connector.

4.

Check harness continuity between HO2S2 terminal 4 and ECM terminal 78.
Refer to Wiring Diagram.

5.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 4.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

Continuity should exist.

BBIA0540E

EC-276

DTC P0137, P0157 HO2S2

2006 Pathfinder

4. 

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.

2.

Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.

3.

Also check harness for short to power.

OK or NG

OK

>> GO TO 5.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

5. 

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-276, "Component Inspection"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Replace malfunctioning heated oxygen sensor 2.

6. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-144, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

UBS00KD5

HEATED OXYGEN SENSOR 2

 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 1 minute.

DTC

Terminals

Bank

ECM

Sensor

P0137

74

1

1

P0157

55

1

2

Continuity should exist.

DTC

Terminals

Bank

ECM

Sensor

P0137

74

1

1

P0157

55

1

2

Continuity should not exist.

SEF174Y

DTC P0137, P0157 HO2S2

EC-277

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2006 Pathfinder

6.

Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.

7.

Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to 

±

25%.

“HO2S2 (B1)/(B2)” should be above 0.68V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is 

−

25%.

CAUTION:

●

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.

●

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 with “OD” OFF.
The voltage should be below 0.18V at least once during this
procedure.

8.

If NG, replace heated oxygen sensor 2.

CAUTION:

●

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.

●

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.

PBIB1672E

PBIB2534E

PBIB1607E

EC-278

DTC P0137, P0157 HO2S2

2006 Pathfinder

Removal and Installation

UBS00KD6

HEATED OXYGEN SENSOR 2

Refer to 

EM-22, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

DTC P0138, P0158 HO2S2

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2006 Pathfinder

DTC P0138, P0158 HO2S2

PFP:226A0

Component Description

UBS00K6T

The heated oxygen sensor 2, after three way catalyst (manifold),
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

UBS00K6U

Specification data are reference values.

On Board Diagnosis Logic

UBS00K6V

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 (manifold) 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)

●

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

–

Engine: After warming up

–

Keeping engine speed between 3,500 and 4,000 rpm for 1 minute and at 
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

EC-280

DTC P0138, P0158 HO2S2

2006 Pathfinder

DTC Confirmation Procedure

UBS00P0E

Perform PROCEDURE FOR MALFUNCTION A first.
If DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
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.

PROCEDURE FOR MALFUNCTION A

 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-285, "Diagnostic Procedure"

.

 With GST

Follow the procedure “WITH CONSULT-II” above.

PROCEDURE FOR MALFUNCTION B

 With CONSULT-II

TESTING CONDISION:
For better results, perform DTC WORK SUPPORT at a temperature of 0 to 30 

°

C (32 to 86 

°

F).

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 1 minute.

6.

Make sure that “COOLAN TEMP/S” indicates more than 70

°

C

(158

°

F).

If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70

°

C (158

°

F).

7.

Open engine hood.

8.

Select “HO2S2 (B1) P1146” (for DTC P138) or “HO2S2 (B2) P1166” (for DTC P0158) of “HO2S2” in “DTC
WORK SUPPORT” mode with CONSULT-II.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0138
0138
(Bank 1)

Heated oxygen sensor 2 cir-
cuit high voltage

A)

An excessively high voltage from the 
sensor is sent to ECM.

●

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

●

Heated oxygen sensor 2

P0158
0158
(Bank 2)

B)

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

●

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

●

Heated oxygen sensor 2

●

Fuel pressure

●

Fuel injector

SEF174Y

SEF174Y

DTC P0138, P0158 HO2S2

EC-281

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2006 Pathfinder

9.

Start engine and following the instruction of CONSULT-II.

NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.

10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”.

If “NG” is displayed, refer to 

EC-285, "Diagnostic Procedure"

 .

If “CAN NOT BE DIAGNOSED” is displayed, perform the following.

a.

Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).

b.

Return to step 1.

Overall Function Check

UBS00KCT

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 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 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 with “OD” OFF.
The voltage should be below 0.18V at least once during this
procedure.

8.

If NG, go to 

EC-285, "Diagnostic Procedure"

 .

PBIB2372E

PBIB1607E

EC-282

DTC P0138, P0158 HO2S2

2006 Pathfinder

Wiring Diagram

UBS00K6X

BANK 1

BBWA2366E