Nissan Qashqai (2007-2010). Manual - part 334

P1146 HO2S2

EC-855

< COMPONENT DIAGNOSIS >

[MR20DE (WITH EURO-OBD)]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors E7, F121
• Harness for open or short between heated oxygen sensor 2 and ECM.

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

7.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-858, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 9.

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:0000000001089437

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.

EC-856

< COMPONENT DIAGNOSIS >

[MR20DE (WITH EURO-OBD)]

P1146 HO2S2

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%.

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.

PBIB0551E

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.

P1146 HO2S2

EC-857

< COMPONENT DIAGNOSIS >

[MR20DE (WITH EURO-OBD)]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

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.

>> INSPECTION END

ECM

Ground

Condition

Voltage

Connector

Terminal

F8

50

(HO2S2 signal)

Ground

Coasting from 80 km/h (50 MPH) in D po-
sition (CVT), 4th gear position (M/T)

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.

EC-858

< COMPONENT DIAGNOSIS >

[MR20DE (WITH EURO-OBD)]

P1147 HO2S2

P1147 HO2S2

Description

INFOID:0000000001089438

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:0000000001115349

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 maximum voltage of the sensor
is sufficiently high during the various driving condition such as fuel-
cut.

DTC CONFIRMATION PROCEDURE

1.

INSPECTION START

Do you have CONSULT-III?
Do you have CONSULT-III?

YES

>> GO TO 2.

NO

>> GO TO 11.

2.

PRECONDITIONING

“COMPLETED” will appear on CONSULT-III screen when all tests “COND1”, “COND2” and “COND3” are
completed.
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
• For the best results, perform 

″

DTC WORK SUPPORT

″

 at a temperature of 0 to 30

°

C (32 to 86

°

F).

• Never stop engine during this procedure. If the engine is stopped, retry this procedure from step 2 in

Procedure for COND1.

CAUTION:

Always drive at safe speed.

SEF327R

SEF259VA

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1146

Heated oxygen sensor 2 
circuit low voltage

The maximum 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
• Intake air leaks