Diagnostic Procedure

RETIGHTEN GROUND SCREWS
1. Turn ignition switch OFF.
2. Loosen and retighten engine ground screws.
  
  Fig 1: Identifying Engine Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  GO TO 2.
RETIGHTEN HEATED OXYGEN SENSOR 1
Loosen and retighten heated oxygen sensor 1.

Tightening torque: 40 - 60 N.m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)

Fig 2: Identifying Heated Oxygen Sensor 1
Courtesy of NISSAN MOTOR CO., U.S.A.
1. GO TO 3.
CLEAR THE SELF-LEARNING DATA
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 P0172 detected?
  
  Is it difficult to start engine?
  
  Fig 3: Displaying WORK SUPPORT Mode With Consult-II
  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, and restart and run engine for at least 5 seconds at idle speed.
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 P0172 detected?
  
  Is it difficult to start engine?
  
  Fig 4: Disconnecting Mass Air Flow Sensor Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
Yes or No
1. Yes: perform trouble diagnosis for DTC P0172. Refer to DTC P0172 FUEL INJECTION SYSTEM FUNCTION .
2. No: GO TO 4.
CHECK HO2S1 CONNECTOR FOR WATER
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Check connectors for water.
  Water should not exist.
  
  Fig 5: Disconnecting Heated Oxygen Sensor 1 Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 5.
2. NG: Repair or replace harness or connectors.
CHECK HEATED OXYGEN SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION ".

OK or NG
1. OK: GO TO 6.
2. NG: Replace heated oxygen sensor 1.
CHECK HEATED OXYGEN SENSOR 1
Refer to "COMPONENT INSPECTION ".

OK or NG
1. OK: GO TO 7.
2. NG: Replace heated oxygen sensor 1.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

For circuit, refer to "WIRING DIAGRAM ".
1. INSPECTION END