KIA Niro: Mass Air Flow Sensor (MAFS)


MAFS uses a sensing element made of a hot-film to measure the mass of intake air entering the engine
and to send the signal to the ECM.

A large amount of intake air represents acceleration or high load conditions while a small amount of
intake air represents deceleration or idle.

The ECM uses this information to control the EGR solenoid valve and correct the fuel amount.

Circuit Diagram

Circuit Diagram

Harness Connector

Harness Connector

Mass Air Flow Sensor (MAFS) Repair procedures

Mass Air Flow Sensor (MAFS) Repair procedures


  1. Visually check the MAFS for the following:
  • Correct mounting direction
  • Any contamination, corrosion or damage on connector
  • Clogged or wet air cleaner
  • Deformation or blocked MAFS cylinder by foreign material
  1. Check for any leakage on intake system and intercooler system.


  1. Switch "OFF" the ignition and disconnect the negative (-) battery terminal.
  2. Disconnect the mass air flow sensor connector (A) and the installation clamp (B).
  3. Remove the mass air flow sensor (C).

Mass air flow sensor mounting bolt : 3.9 - 5.8 N*m (0.4 - 0.6 kgf*m, 2.8 - 4.3 lb*ft) Mass air flow sensor clamp mounting screw : 2.9 - 4.9 N*m (0.3 - 0.5 kgf*m, 2.2 - 3.6 lb*ft)




  • Install the component to the specified torque.
  • Note that internal damage may occur when the component is dropped. In this case, use it after inspecting.


Be careful not to damage the sensing element and the honey cell.

  1. Install in the reverse order of removal.


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