Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten heated oxygen sensor 1.

   Tightening torque : 40 - 60 N.m 

   (4.1 - 6.1 kg-m, 30 - 44 ft-lb) 

   1. GO TO 2.

Fig 1: Identifying Heated Oxygen Sensor 1

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

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.
Fig 2: Scan Tool Display - Work Support
Courtesy of NISSAN MOTOR CO., U.S.A.
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 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, and restart and run engine for at least 3 seconds at idle speed.
Fig 3: Identifying Mass Air Flow Sensor Harness Connector
Courtesy of NISSAN MOTOR CO., U.S.A.
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to "HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION ".
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.

   Is the 1st trip DTC P0171 detected? 

   Is it difficult to start engine? 

Yes or No 

1. Yes: Perform trouble diagnosis for DTC P0171. Refer to DTC P0171 FUEL INJECTION SYSTEM FUNCTION .
2. No: GO TO 3.

Check resistance between terminals 3 and 1.

Resistance :3.3 - 4.0 Ω [at 25°C (77°F)] 

Check continuity between terminals 2 and 1, 3 and 2.

Continuity should not exist. 

Fig 4: Checking Continuity Between Terminals

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

OK or NG 

1. OK: GO TO 4.
2. NG: Replace heated oxygen sensor 1.

Refer to "COMPONENT INSPECTION ".

OK or NG 

1. OK: GO TO 6.
2. NG: Replace heated oxygen sensor 1.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

Refer to "WIRING DIAGRAM ", for circuit description.

1. : INSPECTION END.