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)

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Without Speed Density Update

The Mass Air Flow (MAF) sensor produces a frequency output which is directly proportional to the air entering the engine. The output will vary from approximately 32 Hertz at idle to 150 Hertz during wide open throttle. If the sensor fails at a low frequency, a code 34 will be set and stored. A code 44 or 45 may also be caused by a faulty MAF sensor.