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Home >> Cadillac >> 1989 >> Eldorado >> Repair and Diagnosis >> Engine Performance >> Ignition System - HEI-Est >> Operation >> Est System >> Notes
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Est System: Notes

The ECM monitors crankshaft position, engine RPM, engine load, atmospheric conditions, engine temperature, and transmission gear position. This information is used by the ECM to compute desired spark timing which is relayed to the distributor, enabling appropriate changes to ignition timing.

CAUTION: Although similar in appearance, components with different part numbers are NOT interchangeable.

The distributor module is connected to ECM by a 4-wire EST connector. Wires perform the following functions:

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