Ignition System: Description and Operation

Ignition System Description

The ignition system is of an electronic ignition type that has neither distributor nor high-tension cords. It consists of the following:

- ECM
ECM monitors engine and vehicle conditions through the signals from the relevant sensors, determines the most suitable ignition timing and sends correct signals to ignition coil assemblies.
- Ignition coil assemblies
The ignition coil assembly is a combination of an ignitor and ignition coils. It is provided for each cylinder and the ignition coils fit directly over each spark plug. The current to the primary coil is turned on and off according to the signal from the ECM. When the current flowing through the primary coil is broken, a high voltage is induced in the secondary coil. The high voltage is applied directly to the spark plug of each cylinder.
- Spark plugs
- CMP (camshaft position) sensor and CKP (crankshaft position) sensor
Using signals from these sensors, ECM identifies a specific cylinder whose piston is in the compression stroke, defects the crank angle and adjusts the initial ignition timing automatically.
- TP (throttle position) sensor, ECT (engine coolant temperature) sensor, MAF (mass air flow) sensor, IAT (intake air temperature) sensor, knock sensor and other sensors/switches
ECM controls the ignition timing also using signals from these sensors/switches in addition to signals from the CMP and CKP sensors.