Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten engine ground screws.
   Fig 1: Tightening Engine Ground Screws

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Disconnect heated oxygen sensor 1 harness connector.
   1. GO TO 2.
   Fig 2: Disconnecting Heated Oxygen Sensor Harness Connector

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

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 50 and HO2S1 terminal 2.

   Refer to WIRING DIAGRAM .

   Continuity should exist. 

3. Check harness continuity between ECM terminal 50 or HO2S1 terminal 2 and ground.

   Refer to WIRING DIAGRAM .

   Continuity should not exist. 

4. Also check harness for short to power.

OK or NG 

1. OK: GO TO 3.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.

Refer to COMPONENT INSPECTION .

With CONSULT-II 

OK or NG 

1. OK: GO TO 4.
2. NG: Replace heated oxygen sensor 1.

Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

1. : INSPECTION END.