Nissan Pathfinder (2007 year). Manual - part 218

DTC P2A00, P2A03 A/F SENSOR 1

EC-611

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2007 Pathfinder

Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.

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.

: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)

Diagnostic Procedure

UBS00KEL

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

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

EC-153, "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)

16

BR

A/F sensor 1 (Bank 2)

[Engine is running]

●

Warm-up condition

●

Engine speed: 2,000 rpm

Approximately 1.8V
Output voltage varies with air 
fuel ratio.

24
43

G
G

A/F sensor 1 heater (Bank 2)

[Engine is running]

●

Warm-up condition

●

Idle speed
(More than 140 seconds after starting 
engine)

Approximately 2.9 - 8.8V

75

P

A/F sensor 1 (Bank 2)

[Ignition switch: ON]

Approximately 2.2V

PBIA8148J

BBIA0539E

EC-612

DTC P2A00, P2A03 A/F SENSOR 1

2007 Pathfinder

2. 

RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1

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

>> GO TO 3.

3. 

CHECK FOR INTAKE AIR LEAK

1.

Start engine and run it at idle.

2.

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

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace.

Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)

BBIA0557E

DTC P2A00, P2A03 A/F SENSOR 1

EC-613

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2007 Pathfinder

4. 

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 P0171, P0172, 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 3 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 or P0174, 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-303, "DTC

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION"

   or 

EC-315, "DTC P0172, P0175 FUEL

INJECTION SYSTEM FUNCTION"

 .

No

>> GO TO 5.

SEF968Y

BBIA0541E

EC-614

DTC P2A00, P2A03 A/F SENSOR 1

2007 Pathfinder

5. 

CHECK HARNESS CONNECTOR

1.

Turn ignition switch OFF.

2.

Disconnect A/F sensor 1 harness connector.

3.

Check harness connector for water.

OK or NG

OK

>> GO TO 6.

NG

>> Repair or replace harness connector.

6. 

CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

1.

Turn ignition switch ON.

2.

Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E2, F32

●

IPDM E/R connector E119

●

15A fuse

●

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

>> Repair or replace harness or connectors.

Water should not exit.

BBIA0544E

Voltage: Battery voltage

PBIB3308E

DTC P2A00, P2A03 A/F SENSOR 1

EC-615

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2007 Pathfinder

8. 

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
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 ground and 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 A/F SENSOR 1 HEATER

Refer to 

EC-170, "Component Inspection"

 .

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 11.

10. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-145, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

 OK

>> GO TO 11.

NG

>> Repair or replace.

11. 

REPLACE A/F SENSOR 1

Replace malfunctioning A/F sensor 1.

CAUTION:

●

Discard any 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 A/F sensor, clean exhaust system threads using Heated Oxygen Sensor
Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

>> GO TO 12.

A/F sensor 1 terminal

ECM terminal

Bank1

1

35

2

56

Bank 2

1

16

2

75

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

1

35

1

16

2

56

2

75

Continuity should not exist.

EC-616

DTC P2A00, P2A03 A/F SENSOR 1

2007 Pathfinder

12. 

CONFIRM A/F ADJUSTMENT DATA

1.

Turn ignition switch ON.

2.

Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR”
mode with CONSULT-II.

3.

Make sure that “0” is displayed on CONSULT-II screen.

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 13.

13. 

CREAR A/F ADJUSTMENT 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”.

 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.

>> GO TO 14.

PBIB3202E

SEF968Y

BBIA0541E

DTC P2A00, P2A03 A/F SENSOR 1

EC-617

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2007 Pathfinder

14. 

CONFIRM A/F ADJUSTMENT DATA

1.

Turn ignition switch OFF and then ON.

2.

Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR”
mode with CONSULT-II.

3.

Make sure that “0” is displayed on CONSULT-II screen.

OK or NG

OK

>> INSPECTION END

Removal and Installation

UBS00KEM

AIR FUEL RATIO (A/F) SENSOR 1

Refer to 

EM-22, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 . 

PBIB3202E

EC-618

ASCD BRAKE SWITCH

2007 Pathfinder

ASCD BRAKE SWITCH

PFP:25320

Component Description

UBS00KIP

When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to 

EC-29, "AUTOMATIC SPEED CONTROL DEVICE (ASCD)"

for the ASCD function.

CONSULT-II Reference Value in Data Monitor Mode

UBS00KIQ

Specification data are reference values.

BBIA0560E

MONITOR ITEM

CONDITION

SPECIFICATION

BRAKE SW 1
(ASCD brake switch)

●

Ignition switch: ON

Brake pedal: Fully released

ON

Brake pedal: Slightly depressed

OFF

BRAKE SW 2
(stop lamp switch)

●

Ignition switch: ON

Brake pedal: Fully released

OFF

Brake pedal: Slightly depressed

ON