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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Electronic Spark Control Module: Description and Operation

Electronic Spark Control:






The Electronic Spark Control (ESC) has one major component:

^ ESC knock sensor.

The ESC control module is integrated with the mem-cal. The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The sensor produces a AC output voltage which increases with the severity of the knock. This signal voltage inputs to the ECM. The ECM then adjust the Electronic Spark Timing (EST) to reduce spark knocking.