LEMON Manuals: Even more car manuals for everyone
Home >> Nissan-Datsun >> 2019 >> Altima Edition ONE >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 11 (Engine Control System (DTC/Circuit Diagnosis) (Pr25DD) (4 Of 4)) >> DTC/Circuit Diagnosis >> Mass Air Flow Sensor >> Component Inspection >> PR25DD engine

PR25DD engine

WARNING: This page is about a different variant/trim than selected.
  1. CHECK MASS AIR FLOW SENSOR-1 

    SYMBOL With CONSULT

    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Start engine and warm it up to normal operating temperature.
    4. Connect CONSULT and select "DATA MONITOR" mode of "ENGINE".
    5. Select "MASS AIR FLOW SENSOR (Hz)" and check indication.

      Monitor item

      Condition

      Indication (Hz)

      MASS AIR FLOW SENSOR (Hz)

      Ignition switch ON (Engine stopped.)

      Approx. 3, 700 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    SYMBOL Without CONSULT

    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Start engine and warm it up to normal operating temperature.
    4. Check the frequency between ECM harness connector terminals under the following conditions.

      ECM

      Condition

      Frequency (Hz)

      Connector

      +

      -

      Terminal

      F91

      26

      23

      Ignition switch ON (Engine stopped.)

      Approx. 3, 700 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    GO TO 2.

  2. CHECK FOR THE CAUSE OF UNEVEN AIR FLOW THROUGH MASS AIR FLOW SENSOR 
    1. Turn ignition switch OFF.
    2. Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
      • Crushed air ducts
      • Malfunctioning seal of air cleaner element
      • Uneven dirt of air cleaner element
      • Intake valve deposits
      • Improper specification of intake air system parts

    Is the inspection result normal?

    YES

    GO TO 4.

    NO

    GO TO 3.

  3. CHECK MASS AIR FLOW SENSOR-2 

    SYMBOL With CONSULT

    1. Repair or replace malfunctioning part.
    2. Start engine and warm it up to normal operating temperature.
    3. Connect CONSULT and select "DATA MONITOR" mode of "ENGINE".
    4. Select "MASS AIR FLOW SENSOR (Hz)" and check indication.

      Monitor item

      Condition

      Indication (Hz)

      MASS AIR FLOW SENSOR (Hz)

      Ignition switch ON (Engine stopped.)

      Approx. 3, 720 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    SYMBOL Without CONSULT

    1. Repair or replace malfunctioning part.
    2. Start engine and warm it up to normal operating temperature.
    3. Check the frequency between ECM harness connector terminals under the following conditions.

      ECM

      Condition

      Frequency (Hz)

      Connector

      +

      -

      Terminal

      F91

      26

      23

      Ignition switch ON (Engine stopped.)

      Approx. 3, 700 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    GO TO 4.

  4. CHECK MASS AIR FLOW SENSOR-3 

    SYMBOL With CONSULT

    1. Turn ignition switch OFF.
    2. Disconnect mass air flow sensor harness connector and reconnect it again.
    3. Start engine and warm it up to normal operating temperature.
    4. Connect CONSULT and select "DATA MONITOR" mode of "ENGINE".
    5. Select "MASS AIR FLOW SENSOR (Hz)" and check indication.

      Monitor item

      Condition

      Indication (Hz)

      MASS AIR FLOW SENSOR (Hz)

      Ignition switch ON (Engine stopped.)

      Approx. 3, 700 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    SYMBOL Without CONSULT

    1. Turn ignition switch OFF.
    2. Disconnect MAF sensor harness connector and reconnect it again.
    3. Start engine and warm it up to normal operating temperature.
    4. Check the frequency between ECM harness connector terminals under the following conditions.

      ECM

      Condition

      Frequency (Hz)

      Connector

      +

      -

      Terminal

      F91

      26

      23

      Ignition switch ON (Engine stopped.)

      Approx. 3, 700 Hz

      At 1, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 300 - 5, 800 Hz

      At 2, 500 rpm (Engine is warmed-up to normal operating temperature.)

      5, 800 - 6, 300 Hz

      At 4, 000 rpm (Engine is warmed-up to normal operating temperature.)

      6, 300 - 7, 000 Hz

    Is the inspection result normal?

    YES

    INSPECTION END

    NO

    Clean or replace mass air flow sensor. Refer to Exploded View .

scientia non olet · About LEMON Manuals