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Home >> Infiniti >> 2024 >> Q50 Sensory, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (2 Of 2) >> Component Parts/Circuit Diagnosis >> Mass Air Flow Sensor >> Component Inspection
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Component Inspection

  1. CHECK MASS AIR FLOW SENSOR-I 

    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.
    5. Select "MASS AIR FLOW SENSOR (Hz)" and check the indication.
      Monitor item Condition Indication
      MASS AIR FLOW SENSOR (Hz) Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 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
      Connector + -
      Terminal Terminal
      F143 33
      [MAF sensor (bank 1) signal]      		 30 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz
      35
      [MAF sensor (bank 2) signal]      		 26 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 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-II 

    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.
    4. Select "MASS AIR FLOW SENSOR (Hz)" and check the indication.
      Monitor item Condition Indication
      MASS AIR FLOW SENSOR (Hz) Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 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
      Connector + -
      Terminal Terminal
      F143 33
      [MAF sensor (bank 1) signal]      		 30 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz
      35
      [MAF sensor (bank 2) signal]      		 26 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz

    Is the inspection result normal?

    YES>>

    INSPECTION END

    NO>>

    GO TO 4.

  4. CHECK MASS AIR FLOW SENSOR-III 

    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.
    5. Select "MASS AIR FLOW SENSOR (Hz)" and check the indication.
      Monitor item Condition Indication
      MASS AIR FLOW SENSOR (Hz) Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz

    SYMBOL Without 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. Check the frequency between ECM harness connector terminals under the following conditions.
      ECM Condition Frequency
      Connector + -
      Terminal Terminal
      F143 33
      [MAF sensor (bank 1) signal]      		 30 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz
      35
      [MAF sensor (bank 2) signal]      		 26 Ignition switch ON (Engine stopped.) Approx. 3, 300 Hz
      Idle (Engine is warmed-up to normal operating temperature.) 2, 800 - 3, 100 Hz
      2, 500 rpm (Engine is warmed-up to normal operating temperature.) 2, 100 - 2, 400 Hz
      Idle to about 4, 000 rpm 2, 800 - 3, 100 Hz to Approx. 1, 900 Hz

    Is the inspection result normal?

    YES>>

    INSPECTION END

    NO>>

    Clean or replace malfunctioning mass air flow sensor.

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