Diagnosis Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.

   Refer to "GROUND INSPECTION ".

   Fig 1: Identifying Body Ground (M70 And M16)

   Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

OK: GO TO 2.

NG: Repair or replace ground connections.

1. Loosen and retighten the air fuel ratio (A/F) sensor 1.
   Fig 2: Identifying Retighten Air Fuel Ratio (A/F) Sensor 1

   Courtesy of NISSAN MOTOR CO., U.S.A.

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

   GO TO 3.

1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before three way catalyst (manifold).

Fig 3: Checking Exhaust Gas Leakage

Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

OK: GO TO 4.

NG: Repair or replace malfunctioning part.

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

OK or NG 

OK: GO TO 5.

NG: Repair or replace malfunctioning part.

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, P172, 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 (1) harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness connector.
6. Check that DTC P0102 is displayed.
7. Erase the DTC.
8. Check trhat 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? 

Fig 4: Identifying Mass Air Flow (MAF) Sensor

Courtesy of NISSAN MOTOR CO., U.S.A.

Yes or No 

Yes: Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to "DIAGNOSIS PROCEDURE " or "DIAGNOSIS PROCEDURE ".

No: GO TO 6.

1. Disconnect A/F sensor 1 harness connector.
   Fig 5: Identifying A/F Sensor 1 Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-III or tester.

   Voltage: Battery voltage 

OK or NG 

OK: GO TO  8.

NG: GO TO 7.

Fig 6: Checking Voltage Between A/F Sensor 1 Terminal 3 And Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

Check the following.

• Harness connectors E12, F3
• IPDM E/R harness connector E7
• 15 A fuse
• Harness for open or short between A/F sensor 1 and fuse

  Repair or replace harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as per the following.

   Refer to SYSTEM WIRING DIAGRAMS article.

   ECM CONNECTOR TERMINALS REFERENCE CHART
   
   

   	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  .

4. Check harness continuity between the following terminals and ground.

   Refer to SYSTEM WIRING DIAGRAMS article.

   ECM CONNECTOR TERMINALS REFERENCE CHART
   
   

   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  .

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.

Refer to "COMPONENT INSPECTION ".

OK or NG 

OK: GO TO 10.

NG: GO TO  13.

Refer to "COMPONENT INSPECTION ".

OK or NG 

OK: GO TO 11.

NG: Replace mass air flow sensor.

Refer to "COMPONENT INSPECTION ".

OK or NG 

OK: GO TO 12.

NG: Repair or replace PCV valve.

Perform "DIAGNOSIS PROCEDURE ".

OK or NG 

OK: GO TO 13.

NG: Repair or replace malfunctioning part.

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