Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to GROUND INSPECTION .
  
  Fig 1: Checking Ground Connections
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 2.
2. NG: Repair or replace ground connections.
RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1
Loosen and retighten the air fuel ratio (A/F) sensor 1.

Fig 2: Loosening And Retightening Air Fuel Ratio (A/F) Sensor
Courtesy of NISSAN MOTOR CO., U.S.A.
1. Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
  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 or P0175 detected?
  
  Is it difficult to start engine?
  
  Fig 3: Identifying Self-Learning Screen
  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.
  
  Fig 4: Disconnecting Mass Air Flow Sensor Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Restart engine and let it idle for at least 3 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 P0172 or P0175 detected?
  
  Is it difficult to start engine?
Yes or No
1. Yes: Perform trouble diagnosis for DTC P0172 or P0175. Refer to DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION .
2. No: GO TO 4.
CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
  
  Fig 5: Checking Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check harness connector for water.
  1. Water should not exit.
OK or NG
1. OK: GO TO 5.
2. NG: Repair or replace harness connector.
CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-II or tester.
  
  Fig 6: Checking Voltage Between A/F Sensor 1 Terminal 3 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. Voltage: Battery voltage
OK or NG
1. OK: GO TO 7 .
2. NG: GO TO 6.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E5, F14
- IPDM E/R harness connector E122
- 15A fuse
- Harness for open or short between A/F sensor 1 and fuse
  1. Repair or replace harness or connectors.
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 the following terminals.
  Refer to WIRING DIAGRAM .
  
  Fig 7: Checking Harness Continuity Between Terminals
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. Continuity should exist.
4. Check harness continuity between the following terminals and ground.
  Refer to WIRING DIAGRAM .
  
  Fig 8: Checking Harness Continuity Between Terminals And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. Continuity should not exist.
5. Also check harness for short to power.
OK or NG
1. OK: GO TO 8.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK A/F SENSOR 1 HEATER
Refer to COMPONENT INSPECTION .

OK or NG
1. OK: GO TO 9.
2. NG: Replace A/F sensor 1.
CHECK INTERMITTENT INCIDENT
Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

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