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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Engine Control Module: Description and Operation




The Electronic control unit (ECU) evaluates the data delivered by the various sensors concerning the engine operating conditions, and from this data generates control signals for the differential pressure regulator, the idle control valve, and ignition timing. The ECU also controls warm up enrichment, mixture correction for altitude changes, and ignition timing for changes in fuel quality.