Circuits Affecting Ignition Control

In order to properly control the ignition timing, the PCM relies on the following information:
^ The engine load (manifold pressure or vacuum)
^ The atmospheric (barometric) pressure
^ The engine temperature
^ The intake air temperature
^ The crankshaft position
^ The engine speed (RPM)

The ignition Control (IC) system consists of the following components:
^ The ignition coil/modules
^ The 24X crankshaft position sensor
^ The Powertrain Control Module (PCM)
^ All connecting wires

The ignition control utilizes the following 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 coil/modules. The PCM uses the crankshaft reference signal in order to calculate the amount of spark advance needed.