Ignition System: Description and Operation

GENERAL DESCRIPTION




Interruption of the primary current flowing in the primary side of the ignition coil generates high voltage in the secondary side of the ignition coil. The high voltage thus generated is directed by the distributor to the applicable spark plug. The engine firing order is 1-2-3-4-5-6 cylinders.

On application of high voltage, the spark plug generates as park to ignite the compressed air fuel mixture in the combustion chamber.

The engine control module makes and breaks the primary current of the ignition coil to regulate the ignition timing.

The engine control module detects the crankshaft position by the crankshaft position sensor mounted on the engine to provide ignition at the most appropriate timing for the engine operating condition. When the engine is cold or operated at a high altitude, the ignition timing is slightly advanced to provide optimum performance to the operating condition.

When the transaxle shifts gears, ignition timing is retarded to reduce output torque and alleviate shock during shifting.

OPERATION
- Turn ignition switch to "ON" position, and battery positive voltage will be applied to primary winding of ignition coil.
- When crankshaft position sensor signal is input to engine control module, ON-OFF control of ignition power transistor is performed by engine control module.
- When ignition power transistor is turned on, current flows from ignition coil (primary winding) to ground through ignition power transistor.
- When ignition power transistor is turned off, high voltage is generated in primary winding of ignition coil which induces even higher voltage in the secondary winding, causing a spark at the spark plug(s).