Ignition System: Description and Operation

ENGINE IGNITION

The electronic ignition (EI) system is a coil-on-plug ignition system. The coil-on-plug ignition system consists of the following components:

- Ignition coil-on-plugs
- Spark plugs
- Crankshaft position (CKP) sensor
- Camshaft position (CMP) sensor

The ignition coil-on-plugs:

- change low voltage signals from the PCM to high-voltage pulses.
- supply the high-voltage pulses to the spark plugs.
- are connected directly to each spark plug.
- have replaceable coil boots (2.5L).

The spark plugs:

- change high-voltage pulses into a spark which ignites the fuel and air mixture.

The CKP sensor:

- is a variable reluctance sensor.
- is triggered by a 36-minus-1 tooth trigger wheel mounted on the crankshaft.
- provides base timing and crankshaft speed (RPM) to the PCM.

The CMP sensor (2.5L):

- is a variable reluctance sensor.
- provides camshaft rotational location information to the PCM.

The CMP sensor (3.0L):

- is a Hall-effect sensor.
- is mounted in the front cover.
- is triggered by the high point mark on the intake camshaft trigger wheel.
- provides camshaft rotational location information to the PCM.