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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Ignition Timing Control

PURPOSE
To provide the proper ignition timing for all engine operating conditions.


OPERATION
The Engine Control Module (ECM) contains memories for basic ignition timing at various engine speeds and manifold pressures (engine load). Ignition timing is also adjusted for coolant temperature. The ignition timing control is electronic with no vacuum or mechanical distributor controls.