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 Control Assembly (ECA)


The EEC-IV processor determines spark angle using the Profile Ignition Pick-up (PIP) signal to establish base timing. Spark Output (SPOUT) is sent from the EEC-IV processor to the Distributorless Ignition System (DIS) module and serves two purposes; the leading edge fires the coil and the trailing edge controls the dwell time. This feature is called Computer Controlled Dwell (CCD). For diagnosis and testing of EEC-IV related components (Coolant Sensor, Throttle Position Sensor, Knock Sensor ...... etc.) refer to COMPUTERIZED ENGINE CONTROLS.