Kia_Sephia_Rio_Spectra_Optima_1998-2006

Mass Air Flow (MAF) Sensor

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Operation



The MAF is measured by detection of heat transfer from a hot film probe because the change of the mass air flow rate causes change in the amount of heat being transferred from the hot film probe surface to the air flow. The air flow sensor generates a pulse so it repeatedly opens and closes between the voltage (5V) supplied from the ECM. This results in a change of the temperature of the hot film probe and in the change of resistance.

On 2001-2005 vehicles, this sensor is the most direct method of measuring engine load because it measures the mass of air intake. The MAF sensor provides a signal to the ECM for incoming air temperature. This information is used to adjust the injector pulse width and in turn the air/fuel ratio. On 2006 vehicles this sensor is an air mass flowmeter, which operates on the principle of hot film anemometry. A heated element is placed within the air stream, and maintained at a constant temperature above the air temperature. The amount of electrical power required to maintain the heated element at the proper temperature is a direct function of the flow rate of the air mass past the element. The ECM/PCM uses this information to determine the injection duration and ignition timing of the desired air/fuel ratio.

The MAF provides a signal to the ECM for incoming air temperature. This information is used to adjust the injector pulse width and in turn the air/fuel ratio.

Location



The MAF is mounted in the intake air hose of the air cleaner assembly. On some vehicles this sensor is combined with the IAT sensor.

Removal & Installation



  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the connector from the sensor.
  4.  
  5. Remove the air cleaner and air intake assembly, as required.
  6.  
  7. Remove the sensor from its mounting.
  8.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  

2001-2005

NOTE
Do not drop or subject the sensor to shock. Do not put objects inside the sensor.

  1. Disconnect the sensor electrical connector.
  2.  
  3. Loosen the air intake hose retaining clamps on both sides of the sensor.
  4.  
  5. Disconnect the air intake hose from the sensor.
  6.  
  7. Remove the two bolts attaching the sensor to the mounting bracket.
  8.  
  9. Remove the sensor.
  10.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  
  3. Torque the retaining screws to 69-96 inch lbs.
  4.  

2006
  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the connector from the sensor.
  4.  
  5. Remove the sensor retaining screws.
  6.  
  7. Remove the sensor from its mounting.
  8.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  

Location



This sensor is located in the air intake plenum assembly.

Removal & Installation



  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the connector from the sensor.
  4.  
  5. Remove the air cleaner and air intake assembly, as required.
  6.  
  7. Remove the sensor from its mounting.
  8.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  

2001-2005

NOTE
Do not drop or subject the sensor to shock. Do not put objects inside the sensor.

  1. Disconnect the sensor electrical connector.
  2.  
  3. Loosen the air intake hose retaining clamps on both sides of the sensor.
  4.  
  5. Disconnect the air intake hose from the sensor.
  6.  
  7. Remove the two bolts attaching the sensor to the mounting bracket.
  8.  
  9. Remove the sensor.
  10.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  
  3. Torque the retaining screws to 69-96 inch lbs.
  4.  

2006
  1. Disconnect the negative battery cable.
  2.  
  3. Disconnect the connector from the sensor.
  4.  
  5. Remove the sensor retaining screws.
  6.  
  7. Remove the sensor from its mounting.
  8.  

To install:

  1. Installation is the reverse of the removal procedure.
  2.  

Testing



2000-2003
  1. Allow the engine to reach operating temperature.
  2.  
  3. Let the engine idle.
  4.  
  5. Connect a voltmeter between terminal 4 (red//wht).
  6.  
  7. Verify that the voltage varies between 0.8-1.2 volts.
  8.  
  9. Rev the engine and verify that the voltage varies between 3.5-4.0 volts. If not within specification, replace the sensor.
  10.  

2001-2003
  1. Using a voltmeter check the output voltage of the sensor.
  2.  
  3. On 2001 2.4L and 2.5L engines specification should be 0.5 volt at idle and 1.0 volt at 2000 rpm.
  4.  
  5. On 2002-2003 vehicles with 2.4L engine specification should be 1.2-1.6 volts at idle.
  6.  
  7. On 2002-2003 vehicles with 274L engine specification should be 0.6-1.0 volt at idle.
  8.  
  9. Replace the sensor, as required.
  10.  

2001-2005
  1. Allow the engine to reach operating temperature.
  2.  
  3. Connect a voltmeter between terminal 2 (G/L) and ground.
  4.  
  5. Verify that the voltage varies between 0.6-4.0 volts.
  6.  
  7. If not within specification, replace the sensor.
  8.  

2004-2005
  1. Be sure that the ECM and the MAFS connectors are connected.
  2.  
  3. Connect the scan tool to the data link connector.
  4.  
  5. Start the engine.
  6.  
  7. Monitor the MAPS signals.
  8.  
  9. Specification should be 0.6-1.0 volt at idle and 1.7-2.0 volts at 3000 rpm.
  10.  
  11. Replace the sensor, as required.
  12.  

2004-2006
  1. Using a voltmeter check the sensor output voltage.
  2.  
  3. On 2.4L engine specification should be as follows:

    Intake air quantity 15 kg/h, output voltage 1.40 volts
     
    Intake air quantity 30 kg/h, output voltage 1.77 volts
     
    Intake air quantity 60 kg/h, output voltage 2.24 volts
     
    Intake air quantity 120 kg/h, output voltage 2.82 volts
     
    Intake air quantity 250 kg/h, output voltage 3.54 volts
     
    Intake air quantity 370 kg/h, output voltage 3.97 volts
     
    Intake air quantity 480 kg/h, output voltage 4.28 volts
     

  4.  
  5. On 2.7L engine specification should be as follows:

    Intake air quantity 7.34 kg/h, output voltage 0.3 volt
     
    Intake air quantity 10.06 kg/h, output voltage 0.5 volt
     
    Intake air quantity 19.85 kg/h, output voltage 1.0 volt
     
    Intake air quantity 35.58 kg/h, output voltage 1.50 volts
     
    Intake air quantity 58.79 kg/h, output voltage 2.0 volts
     
    Intake air quantity 94.70 kg/h, output voltage 2.5 volts
     
    Intake air quantity 149.07 kg/h, output voltage 3.0 volts
     
    Intake air quantity 226.66 kg/h, output voltage 3.5 volts
     
    Intake air quantity 335.66 kg/h, output voltage 4.0 volts
     
    Intake air quantity 500.16 kg/h, output voltage 4.5 volts
     
    Intake air quantity 614.61 kg/h, output voltage 4.76 volts
     
    Intake air quantity 730.01 kg/h, output voltage 5.0 volts
     

  6.  
  7. If not within specification, replace the sensor.
  8.  
  9. If within specification, erase the DTC code. If code is reset replace the ECM with a known good component and recheck. Replace the ECM, as required.
  10.  

2006
  1. Connect the scan tool. Turn the engine ON.
  2.  
  3. Install the scan tool and monitor the MASS AIR FLOW parameter on the scan tool data list.
  4.  
  5. Specification should be 0.6-1.0 volt at idle and no load.
  6.  
  7. If within specification, check for poor connection between the PCM and the component.
  8.  
  9. If not, substitute the sensor with a known good component, check for proper operation. If problem corrected replace the sensor.
  10.  

 
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