Operation CHARM: Car repair manuals for everyone.

Ignition System: Description and Operation

The ignition system consists of the following:
^ Crankshaft Position (CKP) sensor
^ ignition coil
^ spark plug wire
^ spark plug

The ignition system is:
^ an Electronic Distributorless Ignition System (EDIS) is controlled by an electronic engine control integrated into the Powertrain Control Module (PCM).
^ set at 10 degrees Before Top Dead Center (BTDC) for base timing, and is not adjustable.

The crankshaft position (CKP) sensor:
^ is a variable reluctance sensor.
^ senses a missing tooth on the crankshaft damper pulse ring.
^ generates a crankshaft position signal which is sent to the PCM. The PCM counts this signal for engine rpm.

The ignition coil:
^ changes low voltage pulses from the PCM to high voltage pulses.
^ has three transformers.
^ fires two spark plugs simultaneously.

Spark plug wires carry high voltage pulses from the ignition coil to the spark plugs.

The spark plugs:
^ change high voltage pulses to spark at the gap, which ignites the fuel and air mixture.