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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Inhibitor Switch

PURPOSE
The Inhibitor Switch signals the Engine Control Module (ECM) of gear position.

OPERATION
The ECM uses the Inhibitor Switch signal to make sure fuel cut does not happen unless the transmission is in gear. This prevents engine dying during deceleration. Inhibitor Switch signals are created in Neutral and Park positions.