Electronic Spark Control (ESC)

Chart C-5 Wiring Diagram:

The Electronic Spark Control (ESC) has two major components:

^ ESC Module (part of the MEM-CAL).
^ ESC knock sensor.

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.