Circuits Affecting Ignition Control

In order to properly control the ignition timing, the PCM relies on the following information:
^ The engine load, based on the manifold pressure or vacuum
^ The atmospheric or Barometric Pressure (BARO)
^ The engine temperature
^ The Intake Air Temperature (IAT)
^ The crankshaft position
^ The engine speed (RPM)

The Ignition Control (IC) system consists of the following components:
^ The ignition coils
^ The 24X Crankshaft Position (CKP) sensor
^ The Powertrain Control Module (PCM)
^ All connecting wires

The ignition control uses the following signals and circuits in order to control the spark timing functions:
^ The 24X signal - The 24X crankshaft position sensor sends a signal to the PCM. The PCM uses this signal in order to determine the crankshaft position. The PCM also utilizes this signal in order to trigger the fuel injectors.
^ The Ignition Control (IC) circuits - The PCM uses these circuits in order to trigger the ignition coils.