Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten engine ground screws. See Figure .
3. Disconnect corresponding heated oxygen sensor 2 harness connector. SeeFigure .
4. Disconnect ECM harness connector.

1. : GO TO 2.

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

   Refer to Wiring Diagram.

   Fig 1: Displaying Terminal Continuity Between ECM & HO2S2

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check harness continuity between ECM terminal or HO2S2 terminal and ground as follow.

   Refer to Wiring Diagram.

   Fig 2: Terminal Continuity

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. 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.

1. Check harness continuity between HO2S2 terminal 4 and engine ground.

   Refer to Wiring Diagram.

   Continuity should exists. 

2. Also check harness for short to power.

   OK or NG 

1. OK: GO TO  5 .
2. NG: GO TO 4.

Check the following.

• Joint connector-18
• Harness for open and short between HO2S2 and engine ground

1. : Repair open circuit or short to power in harness or connectors.

Check heated oxygen sensor connector 2 and harness connector for water.

Water should not exists. 

OK or NG 

1. OK (With CONSULT-II): GO TO 6.
2. OK (Without CONSULT-II): GO TO 7.
3. NG: Repair or replace harness or connectors.

With CONSULT-II 

1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch ON and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least one minute under no lead.
4. Let engine idle for one minute.
5. Select FUEL INJECTION in ACTIVE TEST mode, and select HO2S2 (B1)/(B2) as the monitor item with CONSULT-II.
6. Check HO2S2 (B1)/(B2) at idle speed when adjusting FUEL INJECTION to +/-25%.
   Fig 3: Displaying Voltage Specification Of HO2S2

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

   HO2S2 (B1)/(B2) should be above 0.63V at least once when the FUEL INJECTION is +25%. 

   HO2S2 (B1)/(B2) should be below 0.48V at least once when the FUEL INJECTION is -25%. 

   CAUTION:

   • Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
   • Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

   OK or NG 

1. OK: GO TO  9 .
2. NG: Replace malfunctioning heated oxygen sensor 2.

Without CONSULT-II 

1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch ON and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,0001 rpm for at least one minute under no load.
4. Let engine idle for one minute.
5. Set voltmeter probes between ECM terminal 88 (HO2S2 bank 1 signal) or 90 (HO2S2 bank 2 signal) and engine ground.
6. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.

   (Depress and release accelerator pedal as soon as possible.)

   Fig 4: Checking Heated Oxygen Sensor 2-I

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

OK or NG 

1. OK: GO TO  9 .
2. NG: GO TO 8.

Idle vehicle for 10 minutes, then check voltage between the same terminals as in Test No. 7; or check voltage when coasting from 80 km/h (50 MPH) in D position with ON OFF.

The voltage should go below 0.48V at least once during this procedure. 

OK or NG 

1. OK: GO TO 9.
2. NG: Replace malfunctioning heated oxygen sensor 2.

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

1. : INSPECTION END