Diagnostic Procedure

Which malfunction (A or B) is duplicated?

A or B 

1. A : GO TO  3.
2. B : GO TO 2.

Check the followings for connection.

• Air duct
• Air cleaner
• Vacuum hoses
• Intake air passage between air duct to collector

OK or NG 

1. OK : GO TO 3.
2. NG : Reconnect the parts.

1. Turn ignition switch OFF.
2. Loosen and retighten engine ground screws.
   1. : GO TO 4.
   Fig 1: Tightening Engine Ground Screws

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

1. Disconnect mass air flow sensor harness connector.
2. Turn ignition switch ON.
   Fig 2: Disconnecting Mass Air Flow Sensor Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check voltage between terminal 2 and ground with CONSULT-II or tester.

   Voltage : Battery voltage 

OK or NG 

1. OK : GO TO  6.
2. NG : GO TO 5.
   Fig 3: Checking Voltage Between Terminal And Ground

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

Check the following.

• Harness for open or short between ECM relay and mass air flow sensor
• Harness for open or short between mass air flow sensor and ECM
  1. : Repair harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor terminal 3 and ECM terminal 55. Refer to WIRING DIAGRAM .

   Continuity should exist. 

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

OK or NG 

1. OK : GO TO 7.
2. NG : Repair open circuit or short to ground or short to power in harness or connectors.

1. Check harness continuity between terminal 4 and ECM terminal 54. Refer to WIRING DIAGRAM .

   Continuity should exist. 

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

OK or NG 

1. OK : GO TO 8.
2. NG : Repair open circuit or short to ground or short to power in harness or connectors.

1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Start engine and warm it up to normal operating temperature.
4. Check voltage between ECM terminal 54 (mass air flow sensor signal) and ground.
   Fig 4: Mass Air Flow Sensor Signal Voltage Chart

   Courtesy of NISSAN MOTOR CO., U.S.A.
   Fig 5: Checking Voltage Between ECM Terminal And Ground

   Courtesy of NISSAN MOTOR CO., U.S.A.
5. If the voltage is out of specification, disconnect mass air flow sensor harness connector and connect it again. Repeat above check.
6. If NG, remove mass air flow sensor from air duct. Check hot wire for damage or dust.
   Fig 6: Identifying Mass Air Flow Sensor

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

OK or NG 

1. OK : GO TO 9.
2. NG : Replace mass air flow sensor.

Perform TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

1. : INSPECTION END.