Diagnostic Procedure

RETIGHTEN HEATED OXYGEN SENSOR 1
1. Turn ignition switch OFF.
2. Loosen and retighten heated oxygen sensor 1.
  Tightening torque : 40 - 60 N.m
  
  (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
  1. GO TO 2.
Fig 1: Identifying Heated Oxygen Sensor 1
Courtesy of NISSAN MOTOR CO., U.S.A.
CLEAR THE SELF-LEARNING DATA.
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select "SELF-LEARNING CONT" in "ACTIVE TEST" mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching "CLEAR".
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected?

Is it difficult to start engine?

Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 3 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness connector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to "HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION ".
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 detected?

Is it difficult to start engine?

Yes or No
1. Yes: Perform trouble diagnosis for DTC P0172. Refer to DTC P0172 FUEL INJECTION SYSTEM FUNCTION .
2. No: GO TO 3.
Fig 3: Identifying Mass Air Flow Sensor Harness Connector
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 harness connector.
3. Check harness connector for water.
Water should not exit.

OK or NG
1. OK: GO TO 4.
2. NG: Repair or replace harness connector.
CHECK HEATED OXYGEN SENSOR 1 HEATER
Check resistance between terminals 3 and 1.

Resistance : 3.3 - 4.0 Ω [at 25°C (77°F)]

Check continuity between terminals 2 and 1, 3 and 2.

Fig 4: Checking Continuity Between Terminals
Courtesy of NISSAN MOTOR CO., U.S.A.

Continuity should not exist.
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 5.
2. NG: Replace heated oxygen sensor 1.
CHECK HEATED OXYGEN SENSOR 1
Refer to , "COMPONENT INSPECTION ".

OK or NG
1. OK: GO TO 7.
2. NG: Replace heated oxygen sensor 1.
CHECK INTERMITTENT INCIDENT
Perform , "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

Refer to , "WIRING DIAGRAM ", for circuit.
1. : INSPECTION END.