Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
   Fig 1: Checking Ground Connections

   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.
2. Disconnect heated oxygen sensor 2 harness connector.
   Fig 2: Checking HO2S2 Ground Circuit For Open Short

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to WIRING DIAGRAM .
   • Continuity should exist. 
4. 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 and HO2S2 terminal as follows. Refer to WIRING DIAGRAM .
   Fig 3: ECM Terminal HO2S2 Terminal Connection Chart

   Courtesy of NISSAN MOTOR CO., U.S.A.
   • Continuity should exist. 
2. Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .
   Fig 4: ECM Terminal HO2S2 Terminal Connection Chart

   Courtesy of NISSAN MOTOR CO., U.S.A.
   • 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 connectors for water.

Water should not exist. 

OK or NG

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

Refer to "COMPONENT INSPECTION ".

OK or NG

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

Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

• : INSPECTION END