Diagnosis Procedure

INSPECTION START
Which malfunction (A or B) is duplicated?

A or B

A : GO TO 3.

B : GO TO 2.
CHECK INTAKE SYSTEM
Check the following for connection.
- Air duct
- Vacuum hoses
- Intake air passage between air duct and intake manifold
OK or NG

OK: GO TO 3.

NG: Reconnect the parts.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to "GROUND INSPECTION ".

Fig 1: Identifying Body Ground (M70 And M16)
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 4.

NG: Repair or replace ground connections.
CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor (1) harness connector.
2. Turn ignition switch ON.
  
  Fig 2: Identifying Mass Air Flow (MAF) Sensor
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Check voltage between MAF sensor terminal 2 and ground with CONSULT-III or tester.
Voltage: Battery voltage

OK or NG

OK: GO TO 6.

NG: GO TO 5.

Fig 3: Checking Voltage Between MAF Sensor Terminal 2 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E108, M15
- Harness connectors M72, F102
- Harness for open or short between mass air flow sensor and ECM
- Harness for open or short between mass air flow sensor and IPDM E/R
Repair open circuit or short to ground or short to power in harness or connectors.
CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
  Refer to SYSTEM WIRING DIAGRAMS article.
  
  Continuity should exist .
4. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 7.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
  Refer to SYSTEM WIRING DIAGRAMS article.
  
  Continuity should exist .
2. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 8.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 9.

NG: Replace intake air temperature sensor.
CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 10.

NG: Replace EVAP control system pressure sensor.
CHECK MASS AIR FLOW SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 11.

NG: Replace mass air flow sensor.
CHECK INTERMITTENT INCIDENT
Refer to "DIAGNOSIS PROCEDURE ".

INSPECTION END