Nissan Murano Z50 (2005 year). Manual - part 110

DTC P1274, P1284 A/F SENSOR 1

EC-515

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4.

Clear the self-learning coefficient by touching “CLEAR”.

5.

Turn ignition switch OFF and wait at least 10 seconds.

6.

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

7.

Let engine idle for 1 minute.

8.

Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.

9.

If 1st trip DTC is detected, go to 

EC-519, "Diagnostic Procedure"

.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds.

3.

Disconnect mass air flow sensor harness connector.

4.

Start engine and let it idle for at least 5 seconds.

5.

Stop engine and reconnect mass air flow sensor harness con-
nector.

6.

Select Service $03 with GST and make sure that DTC P0102 is
detected.

7.

Select Service $04 with GST and erase the DTC P0102.

8.

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

9.

Let engine idle for 1 minute.

10. Keep engine speed between 2,500 and 3,000 rpm for 20 min-

utes.

11. Select Service $07 with GST.

If 1st trip DTC is detected, go to 

EC-519, "Diagnostic Procedure"

 .

SEF968Y

PBIB1353E

EC-516

DTC P1274, P1284 A/F SENSOR 1

Revision: 2005 August

2005 Murano

Wiring Diagram 

ABS00A6U

BANK 1

TBWA0692E

DTC P1274, P1284 A/F SENSOR 1

EC-517

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Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

16

LG/B

A/F sensor 1 (Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 3.1V

35

O/L

Approximately 2.6V

56

BR/Y

Approximately 2.3V

75

Y/R

Approximately 2.3V

EC-518

DTC P1274, P1284 A/F SENSOR 1

Revision: 2005 August

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BANK 2

TBWA0693E

DTC P1274, P1284 A/F SENSOR 1

EC-519

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Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

ABS00A6V

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws on the body.
Refer to 

EC-166, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2. 

RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1

Loosen and retighten the air fuel ratio (A/F) sensor 1.

>> GO TO 3.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

57 P

A/F sensor 1 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 2.6V

58

SB

Approximately 2.3V

76

G/Y

Approximately 3.1V

77

LG

Approximately 2.3V

PBIB1835E

Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)

PBIB2291E

EC-520

DTC P1274, P1284 A/F SENSOR 1

Revision: 2005 August

2005 Murano

3. 

CLEAR THE SELF-LEARNING DATA.

 With CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.

3.

Clear the self-learning control coefficient by touching “CLEAR”.

4.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

 Without CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF.

3.

Disconnect mass air flow sensor harness connector.

4.

Restart engine and let it idle for at least 5 seconds.

5.

Stop engine and reconnect mass air flow sensor harness con-
nector.

6.

Make sure DTC P0102 is displayed.

7.

Erase the DTC memory. Refer to 

EC-60, "HOW TO ERASE

EMISSION-RELATED DIAGNOSTIC INFORMATION"

 .

8.

Make sure DTC P0000 is displayed.

9.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0172 or P0175. Refer to 

EC-255

 .

No

>> GO TO 4.

SEF968Y

PBIB1353E

DTC P1274, P1284 A/F SENSOR 1

EC-521

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4. 

CHECK HARNESS CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect A/F sensor 1 harness connector.

3.

Check harness connector for water. 
Water should not exit.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace harness connector.

5. 

CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT

1.

Turn ignition switch ON.

2.

Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 6.

6. 

CHECK CONDENSER CIRCUIT-I

1.

Turn ignition switch OFF.

2.

Disconnect fuse block (J/B) harness connector M1.

3.

Check resistance between fuse block (J/B) terminal 9A and ground.
Refer to Wiring Diagram. 

4.

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

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 8.

PBIB2293E

Voltage: Battery voltage

PBIB1683E

Resistance: Above 1M

Ω

 at 25

°

C (77

°

F)

EC-522

DTC P1274, P1284 A/F SENSOR 1

Revision: 2005 August

2005 Murano

7. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M82, F102

●

Fuse block (J/B) connector M1

●

15A fuse

●

Harness for open or short between A/F sensor 1 and fuse

>> Repair harness or connectors.

8. 

CHECK CONDENSER CIRCUIT-II

1.

Disconnect condenser harness connectors.

2.

Check harness continuity between fuse block (J/B) terminal 9A and condenser terminal 1, condenser ter-
minal 2 and ground.
Refer to Wiring Diagram. 

3.

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

OK or NG

OK

>> GO TO 9.

NG

>> Repair harness or connectors.

9. 

CHECK CONDENSER

Refer to 

EC-408, "CONDENSER"

 .

OK or NG

OK

>> GO TO 10.

NG

>> Replace condenser.

10. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-157, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Continuity should exist.

DTC P1274, P1284 A/F SENSOR 1

EC-523

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11. 

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

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

4.

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

5.

Also check harness for short to power.

OK or NG

OK

>> GO TO 12.

NG

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

12. 

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-408, "Component Inspection"

 .

OK or NG

OK

>> GO TO 13.

NG

>> Replace A/F sensor 1.

13. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-157, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> Go to 14.

NG

>> Repair or replace.

A/F sensor 1 terminal

ECM terminal

Bank 1

1

16

2

75

5

35

6

56

Bank 2

1

76

2

77

5

57

6

58

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

16

1

76

2

75

2

77

5

35

5

57

6

56

6

58

Continuity should not exist.

EC-524

DTC P1274, P1284 A/F SENSOR 1

Revision: 2005 August

2005 Murano

14. 

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace air fuel ratio (A/F) sensor 1.

CAUTION:

●

Discard any air fuel ratio (A/F) 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 air fuel ratio (A/F) sensor, clean exhaust system threads using Heated Oxy-
gen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

>> INSPECTION END

Removal and Installation

ABS00A6W

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

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

 .

DTC P1276, P1286 A/F SENSOR 1

EC-525

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DTC P1276, P1286 A/F SENSOR 1

PFP:22693

Component Description

ABS00A6X

The A/F sensor is a planar dual-cell limit current sensor. The sensor
element of the A/F sensor is the combination of a Nernst concentra-
tion cell (sensor cell) with an oxygen-pump cell, which transports
ions. It has a heater in the element.
The sensor is capable of precise measurement   = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide   range (0.7 <

 < air).

The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.

An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at   = 1. Therefore, the A/F sensor is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800

°

C (1,292 - 1,472

°

F).

CONSULT-II Reference Value in Data Monitor Mode

ABS00A6Y

Specification data are reference values.

On Board Diagnosis Logic

ABS00A6Z

To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/
F) sensor 1 signal fluctuates according to fuel feedback control.

DTC Confirmation Procedure

ABS00A70

CAUTION:

Always drive vehicle at a safe speed.

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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.

3.

Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.

SEF579Z

SEF580Z

MONITOR ITEM

CONDITION

SPECIFICATION

A/F SEN1 (B1)
A/F SEN1 (B2)

●

Engine: After warming up

Maintaining engine speed at 
2,000 rpm

Fluctuates around 1.5V

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible Cause

P1276
1276
(Bank 1)

Air fuel ratio (A/F) sensor 1 
circuit high voltage

●

The A/F signal computed by ECM from the A/
F sensor 1 signal is constantly approx. 1.5V.

●

Harness or connectors
(The A/F sensor 1 circuit is open or 
shorted.)

●

Air fuel ratio (A/F) sensor 1

P1286
1286
(Bank 2)

EC-526

DTC P1276, P1286 A/F SENSOR 1

Revision: 2005 August

2005 Murano

If the indication is constantly approx. 1.5V and does not fluctuates, go to 

EC-531, "Diagnostic Procedure"

 .

If the indication fluctuates around 1.5V, go to next step.

4.

Select “A/F SEN1 (B1) P1276” or “A/F SEN1 (B2) P1286” of “A/F SEN1” in “DTC WORK SUPPORT”
mode with CONSULT-II.

5.

Touch “START”.

6.

When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen.

If “TESTING” is not displayed after 20 seconds, retry from
step 2.

7.

Release accelerator pedal fully.

NOTE:
Never apply brake during releasing the accelerator pedal.

8.

Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, retry from
step 6.

9.

Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to 

EC-531, "Diagnostic Procedure"

 .

Overall Function Check

ABS00A71

Use this procedure to check the overall function of the A/F sensor 1 circuit.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.

3.

Set D position, then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30
MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.

4.

Repeat steps 2 to 3 for five times.

5.

Stop the vehicle and turn ignition switch OFF.

6.

Wait at least 10 seconds and restart engine.

7.

Repeat steps 2 to 3 for five times.

8.

Stop the vehicle and connect GST to the vehicle.

ENG SPEED

1,000 - 3,200 rpm

Vehicle speed

More than 40 km/h (25 MPH)

B/FUEL SCHDL

1.5 - 9.0 msec

Selector lever

D position

SEF576Z

SEF577Z

SEF578Z

DTC P1276, P1286 A/F SENSOR 1

EC-527

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9.

Make sure that no DTC is displayed.
If the DTC is displayed, go to 

EC-531, "Diagnostic Procedure"

 .

EC-528

DTC P1276, P1286 A/F SENSOR 1

Revision: 2005 August

2005 Murano

Wiring Diagram

ABS00A72

BANK 1

TBWA0692E

DTC P1276, P1286 A/F SENSOR 1

EC-529

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Revision: 2005 August

2005 Murano

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

TERMI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

16

LG/B

A/F sensor 1 (Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 3.1V

35

O/L

Approximately 2.6V

56

BR/Y

Approximately 2.3V

75

Y/R

Approximately 2.3V

EC-530

DTC P1276, P1286 A/F SENSOR 1

Revision: 2005 August

2005 Murano

BANK 2

TBWA0693E