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: Description and Operation

GENERAL INFORMATION

Base ignition timing is not adjustable. By controlling the coil ground circuit, the Powertrain Control Module (PCM) is able to set the base timing and adjust the ignition timing advance. This is done to meet changing engine operating conditions.