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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ISC Duty Cycle

Scan Tool Range 20% to 40%. The ISC Duty Cycle parameter indicates the opening of the throttle valve by the ISC actuator in a measurement of a percentage. The ISC Duty Cycle percentage will increase when the PCM commands a larger throttle valve opening. The ISC Duty Cycle percentage will decrease when the ISC actuator responds to a PCM command for a smaller throttle valve opening.