Diagnostic Procedure

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

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

1. Disconnect heated oxygen sensor 2 harness connector and ECM harness connector.
2. Check harness continuity between ECM terminal 56 and HO2S2 terminal 1.

   Refer to WIRING DIAGRAM .

   Continuity should exist. 

3. Check harness continuity between ECM terminal 56 or HO2S2 terminal 1 and ground.

   Refer to WIRING DIAGRAM .

   Continuity should not exist. 

4. Also check harness for short to ground and short to power.

OK or NG 

1. OK: GO TO  4.
2. NG: GO TO 3.

Check the following.

• Harness connectors M58, F28
• Harness for open or short between heated oxygen sensor 2 and ECM
  1. Repair open circuit or short to ground or short to power in harness or connectors.

1. Check harness continuity between heated oxygen sensor 2 terminal 4 and engine ground.

   continuity should exist. 

2. Also check harness for short to power.

OK or NG 

1. OK: GO TO  6
2. NG: GO TO 5

Check the following.

• Harness connectors M58, F28
• Harness for open or short between heated oxygen sensor 2 and engine ground
  1. Repair open circuit or short to power in harness or connectors

Check heated oxygen sensor 2 harness connector for water.

Water should not exist. 

OK or NG 

1. OK: GO TO 7.
2. NG: Repair or replace harness connector.

Refer to COMPONENT INSPECTION .

OK or NG 

1. OK: GO TO 8.
2. NG: Replace heated oxygen sensor 2.

Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

1. : INSPECTION END.