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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Data Link Connector: Description and Operation





The diagnosis switch terminal included in the monitor coupler in the engine room. When this terminal is grounded, a diagnosis signal is fed to ECM which then outputs idle air control (IAC) duty through duty output terminal.