Nissan Murano Z50 (2005 year). Manual - part 111

DTC P1276, P1286 A/F SENSOR 1

EC-531

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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

ABS00A73

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.

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

EC-532

DTC P1276, P1286 A/F SENSOR 1

Revision: 2005 August

2005 Murano

2. 

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

1.

Disconnect air fuel ratio (A/F) sensor 1 harness connector.

2.

Turn ignition switch ON.

3.

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

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 3.

3. 

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 4.

NG

>> GO TO 5.

4. 

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.

Voltage: Battery voltage

PBIB2293E

PBIB1683E

Resistance: Above 1M

Ω

 at 25

°

C (77

°

F)

DTC P1276, P1286 A/F SENSOR 1

EC-533

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5. 

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 6.

NG

>> Repair harness or connectors.

6. 

CHECK CONDENSER

Refer to 

EC-408, "CONDENSER"

 .

OK or NG

OK

>> GO TO 7.

NG

>> Replace condenser.

7. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-157, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Continuity should exist.

EC-534

DTC P1276, P1286 A/F SENSOR 1

Revision: 2005 August

2005 Murano

8. 

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 9.

NG

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

9. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-157, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> Go to 10.

NG

>> Repair or replace.

10. 

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

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.

DTC P1276, P1286 A/F SENSOR 1

EC-535

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Removal and Installation

ABS00A74

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

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

 .

EC-536

DTC P1278, P1288 A/F SENSOR 1

Revision: 2005 August

2005 Murano

DTC P1278, P1288 A/F SENSOR 1

PFP:22693

Component Description

ABS00A75

The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration 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 1 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

ABS00A76

Specification data are reference values.

On Board Diagnosis Logic

ABS00A77

To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.

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

P1278
1278
(Bank 1)

Air fuel ratio (A/F) sensor 1 
circuit slow response

●

The response (from RICH to LEAN) of the A/F 
signal computed by ECM from A/F sensor 1 
signal takes more than the specified time.

●

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

●

Air fuel ratio (A/F) sensor 1

●

Air fuel ratio (A/F) sensor 1 heater

●

Fuel pressure

●

Fuel injector

●

Intake air leaks

●

Exhaust gas leaks

●

PCV

●

Mass air flow sensor

P1288
1288
(Bank 2)

DTC P1278, P1288 A/F SENSOR 1

EC-537

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DTC Confirmation Procedure

ABS00A78

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.

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 1minute under no load.

4.

Let engine idle for 1 minute.

5.

Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.

6.

Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.

7.

After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.

a.

Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.

b.

Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to 

EC-

147, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

 .

8.

Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.

9.

Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to

EC-147, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE"

 . 

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

RESULT”.
If “NG” is displayed, go to 

EC-542, "Diagnostic Procedure"

 .

PBIB0756E

PBIB1925E

PBIB0758E

EC-538

DTC P1278, P1288 A/F SENSOR 1

Revision: 2005 August

2005 Murano

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Select Service $01 with GST.

3.

Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within 

±

15%.

If OK, go to the following step.
If NG, check the following.

●

Intake air leaks

●

Exhaust gas leaks

●

Incorrect fuel pressure

●

Lack of fuel

●

Fuel injector

●

Incorrect PCV hose connection

●

PCV valve

●

Mass air flow sensor

4.

Turn ignition switch OFF and wait at least 10 seconds.

5.

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

6.

Let engine idle for 1 minute.

7.

Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.

8.

Fully release accelerator pedal and then let engine idle for about 1 minute.

9.

Select Service $07 with GST.
If 1st trip DTC is detected, go to 

EC-542, "Diagnostic Procedure"

 .

DTC P1278, P1288 A/F SENSOR 1

EC-539

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Wiring Diagram

ABS00A79

BANK 1

TBWA0692E

EC-540

DTC P1278, P1288 A/F SENSOR 1

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.

TER-

MINAL 

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

DTC P1278, P1288 A/F SENSOR 1

EC-541

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BANK 2

TBWA0693E

EC-542

DTC P1278, P1288 A/F SENSOR 1

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.

Diagnostic Procedure

ABS00A7A

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 A/F SENSOR 1

Loosen and retighten the A/F sensor (manifold).

>> GO TO 3.

TER-

MINAL 

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

DTC P1278, P1288 A/F SENSOR 1

EC-543

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3. 

CHECK EXHAUST GAS LEAK

1.

Start engine and run it at idle.

2.

Listen for an exhaust gas leak before three way catalyst (manifold).

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace.

4. 

CHECK FOR INTAKE AIR LEAK

Listen for an intake air leak after the mass air flow sensor.

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace.

PBIB1216E

EC-544

DTC P1278, P1288 A/F SENSOR 1

Revision: 2005 August

2005 Murano

5. 

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”
or “START”.

4.

Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 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 P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to 

EC-245, "DTC

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION"

  or 

EC-255, "DTC P0172, P0175 FUEL

INJECTION SYSTEM FUNCTION"

 .

No

>> GO TO 6.

SEF968Y

PBIB1353E

DTC P1278, P1288 A/F SENSOR 1

EC-545

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6. 

CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect A/F sensor 1 harness connector.

3.

Turn ignition switch ON.

4.

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

OK or NG

OK

>> GO TO 12.

NG

>> GO TO 7.

7. 

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 8.

NG

>> GO TO 9.

8. 

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.

Voltage: Battery voltage

PBIB2293E

PBIB1683E

Resistance: Above 1M

Ω

 at 25

°

C (77

°

F)

EC-546

DTC P1278, P1288 A/F SENSOR 1

Revision: 2005 August

2005 Murano

9. 

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 10.

NG

>> Repair harness or connectors.

10. 

CHECK CONDENSER

Refer to 

EC-408, "CONDENSER"

 .

OK or NG

OK

>> GO TO 11.

NG

>> Replace condenser.

11. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-157, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Continuity should exist.