Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

MAF Sensor

The scan tool range is 0.0 to 512 g/s. The Mass Air Flow (MAF) is the MAF input frequency converted to grams of air per second. This indicates the amount of air entering the engine.

The scan tool range is 0 to 32000 Hz. The mass air flow sensor input signal to the PCM is a frequency which varies from around 3000 Hz at idle to above 7000 Hz at Wide-open Throttle (WOT). The PCM converts this frequency signal to grams per second in order to be displayed as mass air flow.