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Nissan Pathfinder (2005 year). Manual - part 207

DTC P1273, P1283 A/F SENSOR 1

EC-507

2005 Pathfinder

CLEAR THE SELF-LEARNING DATA.

With CONSULT-II

Start engine and warm it up to normal operating temperature.

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

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

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

Without CONSULT-II

Start engine and warm it up to normal operating temperature.

Turn ignition switch OFF.

Disconnect mass air flow sensor harness connector.

Restart engine and let it idle for at least 3 seconds.

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

Make sure DTC P0102 is displayed.

Erase the DTC memory. Refer to

EC-61, "HOW TO ERASE

Make sure DTC P0000 is displayed.

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

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0171or P0174. Refer to

EC-246, "DTC P0171, P0174 FUEL

INJECTION SYSTEM FUNCTION"

>> GO TO 4.

SEF968Y

BBIA0541E

EC-508

DTC P1273, P1283 A/F SENSOR 1

2005 Pathfinder

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

Turn ignition switch OFF.

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

Turn ignition switch ON.

Check voltage between air fuel ratio (A/F) sensor 1 terminal 3
and ground with CONSULT-II or tester.

OK or NG

>> GO TO 6.

>> GO TO 5.

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E5, F14

●

IPDM E/R connector E119

●

10A fuse

●

Harness for open or short between air fuel ratio (A/F) sensor 1 and fuse

>> Repair or replace harness or connectors.

Voltage: Battery voltage

BBIA0544E

PBIB1683E

DTC P1273, P1283 A/F SENSOR 1

EC-509

2005 Pathfinder

CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT

Turn ignition switch OFF.

Disconnect ECM harness connector.

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

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

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

OK or NG

>> GO TO 7.

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

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER

Refer to

EC-406, "Component Inspection"

OK or NG

>> GO TO 8.

>> GO TO 9.

CHECK INTERMITTENT INCIDENT

Perform

EC-158, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

OK or NG

>> GO TO 9.

>> Repair or replace.

A/F sensor 1 terminal

ECM terminal

Bank1

Bank 2

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

Continuity should not exist.

EC-510

DTC P1273, P1283 A/F SENSOR 1

2005 Pathfinder

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

UBS00KEM

AIR FUEL RATIO (A/F) SENSOR 1

Refer to

EM-21, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

DTC P1274, P1284 A/F SENSOR 1

EC-511

2005 Pathfinder

DTC P1274, P1284 A/F SENSOR 1

PFP:22693

Component Description

UBS00KEN

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

sor 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 temperature of 700 - 800

C (1,292 - 1,472

F).

CONSULT-II Reference Value in Data Monitor Mode

UBS00KEO

Specification data are reference values.

On Board Diagnosis Logic

UBS00KEP

To judge the malfunction, the A/F signal computed by ECM from the air fuel ratio (A/F) sensor 1 signal is mon-
itored not to be shifted to LEAN side or RICH side.

DTC Confirmation Procedure

UBS00KEQ

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

Start engine and warm it up to normal operating temperature.

Turn ignition switch OFF and wait at least 10 seconds.

Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.

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

P1274
1274
(Bank 1)

Air fuel ratio (A/F) sensor 1
rich shift monitoring

●

The A/F signal computed by ECM from the
air fuel ratio (A/F) sensor 1 signal is shifted
to the rich side for a specified period.

●

Air fuel ratio (A/F) sensor 1

●

Air fuel ratio (A/F) sensor 1 heater

●

Fuel pressure

●

Fuel injector

P1284
1244
(Bank 2)

EC-512

DTC P1274, P1284 A/F SENSOR 1

2005 Pathfinder

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

Turn ignition switch OFF and wait at least 10 seconds.

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

Let engine idle for 1 minute.

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

If 1st trip DTC is detected, go to

EC-516, "Diagnostic Procedure"

WITH GST

Start engine and warm it up to normal operating temperature.

Turn ignition switch OFF and wait at least 10 seconds.

Disconnect mass air flow sensor harness connector.

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

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

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

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

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

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-516, "Diagnostic Procedure"

SEF968Y

BBIA0541E

DTC P1274, P1284 A/F SENSOR 1

EC-513

2005 Pathfinder

Wiring Diagram

UBS00KER

BANK 1

BBWA1730E

EC-514

DTC P1274, P1284 A/F SENSOR 1

2005 Pathfinder

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)

A/F sensor 1 (Bank 1)

[Engine is running]

●

Warm-up condition

●

Idle speed

Approximately 3.1V

Approximately 2.6V

Approximately 2.3V

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