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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EVAP Duty Cycle

Range 0 - 100%
The scan tool indicates the [1][2]EVAP duty cycle that the VCM is commanding. The EVAP duty cycle is a pulse width modulated voltage applied to the purge valve which is displayed as a percentage. A high percentage of EVAP duty cycle would indicate near maximum canister purging.