Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
   Fig 1: Loosen & Retighten Three Ground Screws On The Body

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

OK or NG

• OK: GO TO 2.
• NG: Repair or replace ground connections.

1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
   Fig 2: Disconnecting Air Fuel Ratio 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.
   • Voltage: Battery voltage 

OK or NG

• OK: GO TO  4.
• NG: GO TO 3.

Fig 3: A/F Sensor 1 Terminal 3 & Ground Voltage Test

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

Check the following.

• Harness connectors M15, E108
• Harness connectors E12, F3
• Fuse block (J/B) connector M4
• 15A fuse
• Harness for open or short between A/F sensor 1 and fuse
  • : Repair or replace harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to WIRING DIAGRAM .
   Fig 4: A/F Sensor Terminal & ECM Terminal Specification Table

   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: A/F Sensor Terminal & ECM Terminal BANK 1 & 2 Specifications Table

   Courtesy of NISSAN MOTOR CO., U.S.A.
   • Continuity should not exist. 
5. Also check harness for short to power and short to ground.

OK or NG

• OK: GO TO 5.
• NG: Repair open circuit or short to ground or short to power in harness or connectors.

Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

OK or NG

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