Diagnostic Procedure

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

A or B

A: GO TO 3.

B: GO TO 2.
CHECK INTAKE AIR LEAK
Check the following for connections.
- 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 two ground screws on the body.
  Refer to "GROUND INSPECTION ".
Fig 1: Locating M28 & M54 Body Ground Screws
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 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 MAF sensor terminal 2 and ground with CONSULT-II 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 for open or short between mass air flow sensor and ECM relay
- Harness for open or short between mass air flow sensor and ECM
  : 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. Disconnect TCM harness connector (A/T models).
4. Check harness continuity between the following;
  MAF sensor terminal 3 and ECM terminal 67,
  
  MAF sensor terminal 3 and TCM terminal 42 (A/T models).
  
  Refer to WIRING DIAGRAM .
  
  Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 8.

NG: GO TO 7.
DETECT MALFUNCTIONING PART
Check the following.
- Harness for open or short between mass air flow sensor and ECM.
- Harness for open or short between mass air flow sensor and TCM (A/T models).
  : 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 WIRING DIAGRAM .
  Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 9.

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 10.

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

OK or NG

OK: GO TO 11.

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

OK or NG

OK: GO TO 12.

NG: Replace mass air flow sensor.
CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

: INSPECTION END