Nissan Qashqai (2007-2010). Manual - part 160

P0138 HO2S2

EC-159

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

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P0138 HO2S2

Description

INFOID:0000000001082941

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 heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
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.

DTC Logic

INFOID:0000000001082942

DTC DETECTION LOGIC

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the heated oxygen
sensor 1. The oxygen storage capacity of the three way catalyst (manifold) causes the longer switching time.
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.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

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

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

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 2 minutes.

5.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-160, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001082943

SEF327R

PBIB1848E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0138

Heated oxygen sensor 2 
circuit high voltage

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

EC-160

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

P0138 HO2S2

1.

CHECK GROUND CONNECTION

1.

Turn ignition switch OFF.

2.

Check ground connection E21. Refer to Ground Inspection in 

GI-41, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Disconnect heated oxygen sensor 2 harness connector.

2.

Disconnect ECM harness connector.

3.

Check the continuity between HO2S2 harness connector and ECM harness connector.

4.

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

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F121, E7
• Harness for open or short between HO2S2 and ECM

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

4.

CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check the continuity between HO2S2 harness connector and ECM harness connector.

2.

Check the continuity between HO2S2 harness connector or ECM harness connector and ground.

3.

Also check harness for short to power.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors F121, E7
• Harness for open or short between HO2S2 and ECM

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

6.

CHECK HO2S2 CONNECTOR FOR WATER

Check connectors for water.

HO2S2

ECM

Continuity

Connector

Terminal

Connector

Terminal

E58

1

F8

59

Existed

HO2S2

ECM

Continuity

Connector

Terminal

Connector

Terminal

E58

4

F8

50

Existed

HO2S2

ECM

Ground

Continuity

Connector

Terminal

Connector

Terminal

E58

4

F8

50

Ground

Not existed

P0138 HO2S2

EC-161

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

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Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair or replace harness or connectors.

7.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-161, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> GO TO 8.

8.

REPLACE HEATED OXYGEN SENSOR 2

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 and approved anti-seize lubricant.

>> INSPECTION END

9.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-39, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000001082944

1.

INSPECTION START

Do you have CONSULT-III?

Do you have CONSULT-III?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

CHECK HEATED OXYGEN SENSOR 2

With CONSULT-III

1.

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

2.

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

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.

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

7.

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

±

25%.

“HO2S2 (B1)” should be above 0.68V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)” should be below 0.50V at least once when the “FUEL INJECTION” is 

−

25%.

Water should not exist.

PBIB0551E

EC-162

< COMPONENT DIAGNOSIS >

[HR16DE (WITH EURO-OBD)]

P0138 HO2S2

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

3.

CHECK HEATED OXYGEN SENSOR 2-I

Without CONSULT-III

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.

Check the voltage between ECM harness connector and ground under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 4.

4.

CHECK HEATED OXYGEN SENSOR 2-II

Check the voltage between ECM harness connector and ground under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

CHECK HEATED OXYGEN SENSOR 2-III

Check the voltage between ECM harness connector and ground under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> GO TO 6.

6.

REPLACE HEATED OXYGEN SENSOR 2

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 and approved anti-seize lubricant.

ECM

Ground

Condition

Voltage

Connector

Terminal

F8

50

(HO2S2 signal)

Ground

Revving up to 4,000 rpm under no load at 
least 10 times

The voltage should be above 0.68V at 
least once during this procedure.
The voltage should be below 0.50V at least 
once during this procedure.

ECM

Ground

Condition

Voltage

Connector

Terminal

F8

50

(HO2S2 signal)

Ground

Keeping engine speed at idle for 10 min-
utes

The voltage should be above 0.68V at 
least once during this procedure.
The voltage should be below 0.50V at least 
once during this procedure.

ECM

Ground

Condition

Voltage

Connector

Terminal

F8

50

(HO2S2 signal)

Ground

Coasting from 80 km/h (50 MPH) in 4th 
gear position 

The voltage should be above 0.68V at 
least once during this procedure.
The voltage should be below 0.50V at least 
once during this procedure.