Electronic Ignition System Description

Electronic Ignition System Description
The PCM is responsible for maintaining proper spark and fuel injection timing for all driving conditions. To provide optimum driveability and emissions, the PCM monitors the input signals from the following components in order to
calculate spark timing:
- Engine coolant temperature (ECT) sensor. Intake air temperature (IAT) sensor.
- Throttle position (TP) sensor.
- Vehicle speed sensor (VSS).
- Crankshaft position (CKP) sensor.

Ignition is done by the Ignition Module that fires.
Since the cylinder on exhaust stroke requires less energy to fire its spark plug, energy from the ignition coils can be utilized to fire the mating cylinder on compression stroke. A notch in the timing disc on the crankshaft activates the crank angle sensor which then sends information such as firing order and starting timing of ignition coil to the PCM.

By receiving signals such as crank position, engine speed, water temperature and Manifold Absolute Pressure (MAP), the PCM controls the ignition timing.