The High Energy Ignition (HEI) system uses one coil and two spark plugs per cylinder. Individual coils for each
cylinder ensure consistent performance at high rpms and allow individual cylinder spark control. Dual spark plugs
provide more complete combustion, particularly near the cylinder walls, thus decreasing emissions. Also, HEI
enhances combustion efficiency when firing mixtures diluted by EGR (Exhaust Gas Recirculation), which in turn
improves overall efficiency and lowers emissions.

OPERATION

The ignition system for the 3.2L and the 3.2L SRT-6 engines utilize 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 con-
ditions 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).

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IGNITION SYSTEM - SERVICE INFORMATION

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.

SPECIFICATIONS

SPECIFICATIONS - SPARK PLUGS

DESCRIPTION

SPECIFICATION

Bosch

F8 DPP 332

Champion

7071

RC 12 YC

NGK

IFR5D 10

Spark Plug Gap

.80 mm

0.040 in

Firing Order

1-4-3-6-2-5

SPECIFICATIONS - TORQUE

DESCRIPTION

N·m

Ft. Lbs.

In. Lbs.

Camshaft Position Sensor Bolt

Crankshaft Position Sensor Bolt

Coil Retaining Bolt

Knock Sensor Bolts

177

Spark Plugs

248

IGNITION SYSTEM - SERVICE INFORMATION

8I - 5

CAMSHAFT POSITION SENSOR

DESCRIPTION

The Camshaft Position Sensor is a hall effect type sensor (3 wire). The Camshaft Position Sensor is mounted on
the front of the right cylinder head.

OPERATION

The Camshaft Position Sensor provides cylinder identification to the Powertrain Control Module (PCM). The sensor
generates pulses. The PCM determines engine position from the Camshaft Position Sensor and Crankshaft Position
Sensor inputs. The PCM uses the sensor inputs to determine ignition coil timing, and manage fuel injection syn-
chronization.

The Camshaft Position Sensor is a hall effect type sensor. The Camshaft Position Sensor is used to determine
when cylinder #1 is on the compression stroke.

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IGNITION SYSTEM - SERVICE INFORMATION

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