Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to "GROUND INSPECTION ".
   Fig 1: Identifying ECM Ground Screws On Body

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

OK or NG 

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

1. Disconnect ECM harness connector and A/F sensor 1 harness connector.
   Fig 2: Disconnecting ECM Harness Connector And A/F Sensor 1

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check harness continuity between the following terminals. Refer to WIRING DIAGRAM .
   A/F SENSOR 1 TO ECM TERMINAL CONTINUITY SPECIFICATIONS
   
   

   A/F sensor 1 terminal	ECM terminal
   1	16
   2	75
   5	35
   6	56

   • Continuity should exist  .
3. Check harness continuity between ECM terminals 16, 35, 56, 75 or A/F sensor 1 terminals 1, 2, 5, 6 and ground. Refer to WIRING DIAGRAM .
   • Continuity should not exist  .
4. Also check harness for short to power.

OK or NG 

• OK : GO TO 3.
• 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.