Roadmaster Estate Wagon V8-350 5.7L (1993)
Electronic Spark Timing: Description and Operation
Wiring Diagram For ESC Circuit
Electronic Spark Control (ESC) is accomplished with a module that sends a voltage signal to the ECM. As the sensor detects engine knock, the voltage
from the ESC module to the ECM is reduced. This signals the ECM to retard the timing, if engine speed is over approximately 900 rpm.