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

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Air Flow Meter/Sensor: Description and Operation




A hot wire type mass airflow sensor is used.




Structure and operation
- The mass air flow (MAF) sensor uses a hot wire to measure the amount of mass air intake flow.
- Air passing over the hot wire causes it to cool. This hot wire is maintained preprogrammed temperature above ambient temperature.
- Ambient temperature is measured by a constant cold wire.