Diagnostic Procedure

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

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

OK or NG 

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

1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
   Fig 2: Disconnecting Heated Oxygen Sensor 2 Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.

   Refer to WIRING DIAGRAM .

   • Continuity should exist. 
5. Also check harness for short to ground and 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.

1. Check harness continuity between ECM terminal 74 and HO2S2 terminal 1. Refer to WIRING DIAGRAM .
   • Continuity should exist. 
2. Check harness continuity between ECM terminal 74 or HO2S2 terminal 1 and ground. Refer to WIRING DIAGRAM .
   • Continuity should not exist. 
3. Also check harness for short to power.

OK or NG 

• OK : GO TO 4.
• NG : Repair open circuit or short to ground or short to power in harness or connectors.

Check HO2S2 harness connector for water.

Water should not exist. 

OK or NG 

• OK : GO TO 5.
• NG : Repair or replace harness connector.

Refer to "COMPONENT INSPECTION ".

OK or NG 

• OK : GO TO 6.
• NG : Replace heated oxygen sensor 2.

Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

• : INSPECTION END