Nissan Xterra. Manual - part 324

EC-422

< DTC/CIRCUIT DIAGNOSIS >

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P2096, P2097, P2098, P2099 A/F SENSOR 1

Loosen and retighten the air fuel ratio (A/F) sensor 1 and heated oxygen sensor 2. Refer to 

EC-15, "Engine

Control Component Parts Location"

.

>> GO TO 3.

3.

CHECK FOR EXHAUST GAS LEAK

1. Start engine and run it at idle.

2. Listen for an exhaust gas leak before the three way catalyst 2.
Is exhaust gas detected?

YES

>> Repair or replace.

NO

>> GO TO 4.

4.

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 5.

NG

>> Repair or replace.

5.

CLEAR THE SELF-LEARNING DATA.

 With CONSULT

1. Start engine and warm it up to normal operating temperature.

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

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

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-50, "On Board Diagnosis

Function"

 (Without CONSULT) or 

EC-53, "CONSULT Function"

(With CONSULT).

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-235

 or 

EC-241

.

No

>> GO TO 6.

6.

CHECK HARNESS CONNECTOR

1. Turn ignition switch OFF.

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P2096, P2097, P2098, P2099 A/F SENSOR 1

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2. Disconnect A/F sensor 1 harness connector.

3. Check harness connector for water.

OK or NG

OK

>> GO TO 7.

NG

>> Repair or replace harness connector.

7.

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 or tester.

OK or NG

OK

>> GO TO 9.

NG

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E2, F32

• IPDM E/R connector E119

• 15 A fuse (No.54)

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

>> Repair or replace harness or connectors.

9.

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.

Water should not exit.

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Voltage: Battery voltage

A/F sensor 1 terminal

ECM terminal

Bank1

1

69

2

73

Bank 2

1

77

2

81

Continuity should exist.

Bank 1

Bank 2

A/F sensor 1 terminal

ECM terminal

A/F sensor 1 terminal

ECM terminal

EC-424

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P2096, P2097, P2098, P2099 A/F SENSOR 1

5. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 10.

NG

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

10.

CHECK A/F SENSOR 1 HEATER

Refer to 

EC-160, "Component Inspection"

.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 13.

11.

CHECK HEATED OXYGEN SENSOR 2

Refer to 

EC-213, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Replace heated oxygen sensor 2. Refer to 

EC-15, "Engine Control Component Parts Location"

.

12.

CHECK INTERMITTENT INCIDENT

Perform 

GI-40, "Intermittent Incident"

.

OK or NG

 OK

>> GO TO 13.

NG

>> Repair or replace.

13.

REPLACE A/F SENSOR 1

Replace malfunctioning A/F sensor 1. Refer to 

EC-15, "Engine Control Component Parts Location"

.

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 14.

14.

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.

3. Make sure that “0” is displayed on CONSULT screen.
OK or NG

OK

>> INSPECTION END

NG

>> GO TO 15.

15.

CREAR A/F ADJUSTMENT DATA

 With CONSULT

1. Start engine and warm it up to normal operating temperature.

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

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

 Without CONSULT

1. Start engine and warm it up to normal operating temperature.

2. Turn ignition switch OFF.

1

69

1

77

2

73

2

81

Continuity should not exist.

P2096, P2097, P2098, P2099 A/F SENSOR 1

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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-50, "On Board Diagnosis

Function"

 (Without CONSULT) or 

EC-53, "CONSULT Function"

(With CONSULT).

8. Make sure DTC P0000 is displayed.

>> GO TO 16.

16.

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.

3. Make sure that “0” is displayed on CONSULT screen.
OK or NG

OK

>> INSPECTION END

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