Operation

OPERATION

The ignition system for the 3.2L engine utilizes a Distributorless Ignition System design. The ignition system uses a separate ignition coil pack for each cylinder. The one piece coil pack bolts directly to the cylinder head cover. The coil packs are designed with two secondary towers for each spark plug wire. Rubber boots seal the secondary terminal ends of the spark plug wires. A separate electrical connector is used for each coil pack.

The camshaft position sensor is a hall effect device, and the crankshaft position sensor is an inductive device. The camshaft position sensor and crankshaft position sensor generate pulses that are inputs to the PCM. The PCM determines engine position from these sensors. The PCM calculates injector sequence and ignition timing based on crankshaft & camshaft position.

The two spark plugs per cylinder are fired slightly out of phase to prevent the cylinder pressures from rising too quickly, which could cause knocking. To prevent one spark plug from eroding more quickly than the other, they alternately lead each other. Under normal conditions, the timing is the same for all cylinders, but the timing can be delayed in individual cylinders if knocking is present in one or more.

Two knock sensors are used to control spark knock. Highly sensitive knock sensors can distinguish knocking conditions in individual cylinders and retard the ignition timing as needed on the cylinders that are knocking.

NOTE: All engines use a fixed ignition timing system. Basic ignition timing is not adjustable. All spark advance is determined by the Powertrain Control Module (PCM).

The following components make up the Ignition System:

Spark Plugs

Each cylinder utilizes two spark plugs. The spark plugs use a platinum tip design for extended service life. The spark plugs are mounted directly across from each other in the cylinder head.

Ignition Coil Packs

Each cylinder has its own coil pack. The coil packs are a dual-coil design, utilizing two coils in one. Each coil pack has a single primary input, and two secondary outputs. The coils will fire simultaneously, or in phases. The six coil packs are mounted to the top of the cylinder head covers.

Spark Plug Cables

Each cylinder utilizes two spark plug cables. The cables are shielded for heat protection.

Camshaft Position Sensor

The Camshaft Position Sensor is a hall effect type sensor (3 wire). The Camshaft Sensor is used to identify cylinder #1 compression stroke. The Camshaft Position Sensor is mounted on the right front cylinder head.

Crankshaft Position Sensor

The Crankshaft Position Sensor is an inductive type sensor (2 wire). The Crankshaft Sensor is used to determine the crankshaft position and speed. The Crankshaft Position Sensor is mounted on the left rear of the cylinder block.

Knock Sensors

The knock sensors are Piezo type sensors. The engine is equipped with two knock sensors. The knock sensors monitor vibration of the crankcase, and act to control timing on the relevant cylinder. The Knock Sensors are mounted in the engine valley, just below the intake manifold.

Powertrain Control Module

The PCM uses inputs from the Camshaft Position Sensor, Crankshaft Position Sensor, Knock Sensors, Engine Coolant Temperature Sensor, and MAF Sensor (3.2L engine only) to trigger the Ignition Coils. The PCM is mounted in the engine compartment within the Control Module Box.