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Home >> Nissan-Datsun >> 2004 >> Altima Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Engine Control System - 2.5L >> DTC P0101: Map Sensor >> Diagnostic Procedure
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Diagnostic Procedure

  1. INSPECTION START 

    Which malfunction (A or B) is duplicated?

    A or B

    1. A : GO TO  3.
    2. B : GO TO 2.
  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

    1. OK : GO TO 3.
    2. NG : Reconnect the parts.
  3. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
      Fig 1: Checking Ground Connections
      G02884246Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK : GO TO 4.
    2. NG : Repair or replace ground connections.
  4. CHECK MAP SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect mass air flow (MAF) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 2: Disconnecting Mass Air Flow (MAF) Sensor Harness Connector
      G02884247Courtesy 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

    1. OK : GO TO  6.
    2. NG : GO TO 5.
      Fig 3: Checking Voltage Between MAF Sensor Terminal 2 & Ground
      G02884248Courtesy of NISSAN MOTOR CO., U.S.A.
  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E20, F32
    • Harness for open or short between IPDM E/R and mass air flow sensor
    • Harness for open or short between mass air flow sensor and ECM
    1. Repair harness or connectors.
  6. CHECK MAP 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 Wiring Diagram .

      Continuity should exist. 

    4. Also check harness for short to ground and 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.
  7. 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

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

    Refer to "COMPONENT INSPECTION ".

    OK or NG

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

    Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. >> INSPECTION END 
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