MAF sensor inspection

Remove MAF & IAT sensor. See MASS AIR FLOW (MAF) & INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL AND INSTALLATION .
Connect three new 1.5 V batteries in series and check that total voltage is 4.5 - 5.0 V
Connect 12 V battery (1), 1.5 V batteries (2) and 1.2 kΩ resister (3) to MAF sensor as shown in figure.
Connect oscilloscope (5) or multimeter (4) to MAF sensor as shown in figure.
Check that waveform or frequency varies depending on amount of blowing air to air intake vent (6) using oscilloscope or frequency range of multimeter.
If faulty condition is found, replace MAF & IAT sensor. See MASS AIR FLOW (MAF) & INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL AND INSTALLATION .

MAF sensor waveform (reference)

Calm:

Fig 1: MAF Sensor Waveform Graph (Calm)
Courtesy of SUZUKI OF AMERICA CORP.

Blowing:

Fig 2: MAF Sensor Waveform Graph (Blowing)
Courtesy of SUZUKI OF AMERICA CORP.

Fig 3: Using Oscilloscope Or Frequency Range Of Multimeter
Courtesy of SUZUKI OF AMERICA CORP.