Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to "Ground Inspection ".
   Fig 1: Locating Body Ground Screws

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

OK or NG 

1. OK: GO TO 2.
2. NG: Repair or replace ground connections.

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

Fig 2: Locating Air Fuel Ratio Sensor 1 (Bank 1,2) And Heated Oxygen Sensor 2 (Bank 1,2)

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

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

1. : GO TO 3.

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 or P0174 detected? 

   Is it difficult to start engine? 

   Fig 3: Identifying Self-Learning Control Display In Work Support Mode

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

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 connector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to "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 or P0174 detected? 

   Is it difficult to start engine? 

   Fig 4: Locating Mass Air Flow Sensor With Intake Air Temperature Sensor

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

Yes or No 

1. Yes: Perform trouble diagnosis for DTC P0171 or P0174. Refer to "DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION ".
2. No: GO TO 4.

1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
   Fig 5: Locating A/F Sensor 1 (Bank 1 And 2) Harness Connector By Removing Intake Air Duct

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

   Voltage: Battery voltage 

OK or NG 

1. OK: GO TO  6.
2. NG: GO TO 5.
   Fig 6: Checking Voltage Between A/F Sensor 1 Terminal 3 And Ground With Tester

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

Check the following.

• Harness connectors M72, F102
• Harness connectors E108, M15
• IPDM E/R harness connector E7
• 15A fuse
• Harness for open or short between A/F sensor 1 and fuse

1. : Repair or replace harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals.

   Refer to Wiring Diagram.

   Fig 7: A/F Sensor 1 Terminal And ECM Terminal Relating Table 1 (For Checking Continuity Between Terminal)

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

   Continuity should exist. 

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

   Refer to Wiring Diagram.

   Fig 8: A/F Sensor 1 Terminal And ECM Terminal Relating Table 2 (For Checking Continuity Between Terminal And Ground)

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

   Continuity should not exist. 

5. Also check harness for short to power.

OK or NG 

1. OK: GO TO 7.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.

Refer to "Component Inspection ".

OK or NG 

1. OK: GO TO 8.
2. NG: Replace A/F sensor 1.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

OK or NG 

1. OK: Replace A/F sensor 1.
2. NG: Repair or replace.