Circuits Affecting Ignition Control

To properly control 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 coils
• The 24X crankshaft position sensor
• The powertrain control module (PCM)
• All connecting wires

The ignition control utilizes the following to control spark timing functions:

• The 24X signal-The 24X crankshaft position sensor sends a signal to the PCM. The PCM uses this signal to determine crankshaft position. The PCM also utilizes this signal to trigger the fuel injectors.
• The ignition control (IC) circuits-The PCM uses these circuits to trigger the ignition coils.