Engine Ignition (Description and Operation)

Eight separate ignition coils:

• are controlled by the powertrain control module (PCM).
• are mounted directly above each spark plug.
• are controlled by the powertrain control module for correct firing sequence.

The spark plug:

• changes the high voltage pulse into a spark which ignites the fuel and air mixture.
• originally equipped on the vehicle has a platinum-enhanced active electrode for long life.

The crankshaft position (CKP) sensor:

NOTE: Initial engine ignition timing is set at 10 degrees +- 2 degrees before top dead center (BTDC) and is not adjustable. For additional information, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

• is a variable reluctance sensor, triggered by a 36-minus-1 tooth trigger pulse wheel located on the crankshaft, inside the engine front cover.

The sine wave type signal generated from the crankshaft position sensor provides two types of information:

• position of the crankshaft in 10 degree increments
• the crankshaft speed (rpm)

Engine Ignition (DIAGNOSIS AND TESTING)

Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.