Diagnostic Procedure

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground 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 A/F SENSOR 1
Loosen and retighten the A/F sensor 1.

Fig 2: Retightening A/F Sensor 1
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.
CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
  
  Fig 3: Checking Exhaust Gas Leak
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 4.
2. NG: Repair or replace.
CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.

OK or NG
1. OK: GO TO 5.
2. NG: Repair or replace.
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" or "START".
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?
  
  Fig 4: CONSULT-II Display - "SELF-LEARNING CONT" 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, P0172, P0174 or P0175 detected?
  
  Is it difficult to start engine?
  
  Fig 5: 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, P0174 or P0172, P0175. Refer to "DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION " or "DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION ".
2. No: GO TO 6.
CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
  
  Fig 6: Identifying A/F Sensor 1 Harness Connectors
  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.
  1. Voltage: Battery voltage
  Fig 7: Checking Voltage Between A/F Sensor 1 Terminal 3 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: GO TO 7.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E5, F14
- IPDM E/R harness connector E119
- 10A 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 A/F sensor 1 terminal and ECM terminal as follows. Refer to WIRING DIAGRAM .
  
  Fig 8: A/F Sensor 1 Terminal And ECM Terminal For Checking Harness Continuity
  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 9: A/F Sensor 1 Terminal And ECM Terminal For Checking Harness Continuity
  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 9.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION "

OK or NG
1. OK: GO TO 10.
2. NG: GO TO 13.
CHECK MASS AIR FLOW SENSOR
Refer to "COMPONENT INSPECTION "

OK or NG
1. OK: GO TO 11.
2. NG: Replace mass air flow sensor.
CHECK PCV VALVE
Refer to "COMPONENT INSPECTION ".

OK or NG
1. OK: GO TO 12.
2. NG: Repair or replace PCV valve.
CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT "

OK or NG
1. OK: GO TO 13.
2. NG: Repair or replace.
REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
- Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
1. INSPECTION END