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: Loosening & Retightening Ground Screws
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 2.
- NG: Repair or replace ground connections.
CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
  
  Fig 2: Disconnecting Air Fuel Ratio (A/F) Sensor 1 Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with CONSULT-II or tester.
  
  Fig 3: Checking Voltage Between A/F Sensor 1 Terminal 3 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  - Voltage: Battery voltage
OK or NG
- OK: GO TO 4.
- NG: GO TO 3.
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
- : 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 4: Terminals Sensor Reference Chart
  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 5: Terminals Sensor Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  - Continuity should not exist.
5. Also check harness for short to power.
OK or NG
- OK: GO TO 5.
- NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

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