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.

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Link: lemon-manuals.la

Ignition Timing: Description and Operation

Ignition Timing Control
The PCM contains the memory for basic ignition timing at various engine speeds and manifold absolute pressure. It also adjusts the timing according to engine coolant temperature.









Top Dead Center (TDC) Sensors
The TDC1/TDC2 sensor determines ignition timing at start up (cranking) and when crank angle is abnormal.