Infiniti QX56 (JA60). Manual - part 433

EC-384

< COMPONENT DIAGNOSIS >

[VK56DE]

P2A00, P2A03 A/F SENSOR 1

1. Loosen and retighten the 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.

4.

CLEAR THE SELF-LEARNING DATA

 With CONSULT-III

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

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

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-III

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-459, "DTC Index"

.

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-172

 or 

EC-177

.

No

>> GO TO 5.

5.

CHECK HARNESS CONNECTOR

1. Turn ignition switch OFF.

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

BBIA0375E

BBIA0368E

P2A00, P2A03 A/F SENSOR 1

EC-385

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

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-III or tester.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors E5, F14

• IPDM E/R harness connector E119

• 15A fuse (No. 54)

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

>> Repair or replace harness or connectors.

8.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

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.

BBIA0376E

Voltage: Battery voltage

PBIB3308E

A/F sensor 1 terminal

ECM terminal

Bank1

1

35

2

56

Bank 2

1

16

2

75

Continuity should exist.

EC-386

< COMPONENT DIAGNOSIS >

[VK56DE]

P2A00, P2A03 A/F SENSOR 1

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 A/F SENSOR 1 HEATER

Refer to 

EC-97, "Component Inspection"

.

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 11.

10.

CHECK INTERMITTENT INCIDENT

Perform 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

OK or NG

OK

>> GO TO 11.

NG

>> Repair or replace.

11.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

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

CAUTION:

• Discard any A/F sensor which has been dropped from a height of more than 0.5 m (1.6 ft) onto a hard

surface such as a concrete floor; use a new one.

• Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread

Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

>> GO TO 12.

12.

CONFIRM A/F ADJUSTMENT DATA

1. Turn ignition switch OFF and then ON.

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

3. Make sure that “0.000” is displayed on CONSULT-III screen.
OK or NG

OK

>> INSPECTION END

NG

>> GO TO 13.

13.

CLEAR THE SELF-LEARNING DATA

 With CONSULT-III

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

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

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

 Without CONSULT-III

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

2. Turn ignition switch OFF.

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.

P2A00, P2A03 A/F SENSOR 1

EC-387

< COMPONENT DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

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-55, "Malfunction Indicator

Lamp (MIL)"

.

8. Make sure DTC P0000 is displayed.

>> GO TO 14.

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-III.

3. Make sure that “0.000” is displayed on CONSULT-III screen.

>> INSPECTION END

BBIA0368E