Fleetwood FWD V8-300 4.9L (1993)
Ignition Control Module: Description and Operation
Engine Speed Signal
HEI Wiring Diagram
The engine speed signal comes from a seven terminal High Energy Ignition (HEI) module in the distributor along CKT 430 (DIST REF). Pulses from the
distributor are sent to the PCM/ECM where the duration between these pulses are used to calculate engine speed. The PCM/ECM adjusts spark advance
and sends a signal back to the distributor.
