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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IAC Position

Display shows counts from 0 to 255. This display indicates the commanded position of the Idle Air Control (IAC) valve pintle. When a higher idle engine speed is desired the control module will retract the IAC pintle, increasing airflow and increasing the count value. When a slower idle engine speed is desired the control module will extend the IAC pintle, decreasing airflow and decreasing the count value. 0 counts would indicate a fully closed IAC pintle