4. Check HO2S2 Input Signal Circuit For Open And Short

1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal and HO2S2 terminal as follows.

   Refer to Wiring Diagram.

   Fig 1: Checking HO2S2 Input Signal Circuit For Open & Short

   Courtesy of NISSAN MOTOR CO., U.S.A.
   1. Continuity should exist. 
3. Check harness continuity between the following terminals and ground. See Fig 1.

   Refer to Wiring Diagram.

   1. Continuity should not exist. 
4. Also check harness for short to ground or short to power.

OK or NG 

OK: GO TO 6. CHECK HEATED OXYGEN SENSOR 2 .

NG: GO TO 5.