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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Throttle Position Switch: Description and Operation


The idle (IDL) switch detects when the throttle plate is closed and supplies the information the the ECA. The ECA uses this input to control air/fuel ratio, fuel pressure, idle speed and purge flow. The IDL switch is integrated with throttle position sensor.