Ignition System - Service Information: Overview Chrysler Crossfire I

Scheme 2

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 RPM 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 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

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 synchronization.

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.

Scheme 3

1. Disconnect the negative battery cable.
2. Disconnect the camshaft position sensor harness connector (1).
3. Remove the retaining bolt (2).
4. Remove the camshaft position sensor from the cylinder head.

Scheme 4

Note. Lubricate the camshaft position sensor O-ring with engine oil.

1. Inspect the camshaft position sensor O-ring (1) for damage.
2. Lubricate the camshaft position sensor O-ring as necessary.
3. Position the camshaft position sensor on the cylinder head.
4. Install the retaining bolt (2). Tighten the retaining bolt to 8 N.m (71 in. lbs.).
5. Connect the camshaft position sensor harness connector (1).
6. Connect the negative battery cable.

Scheme 5

The Ignition Coils are mounted on the cylinder head covers. They are connected to the spark plugs via short spark plug cables. The coils are a dual coil type construction. Utilizing two separate coils in one coil pack.

Scheme 6

The Ignition Coils are powered by Fuse 11 in the Underhood Accessory Fuse Block. The Powertrain Control Module (PCM) controls the current flow through the primary side of the coils by toggling the control circuits. The secondary voltage is generated when the primary current flow stops, and the magnetic field created by the current flow in the primary windings collapses. The collapsing magnetic field induces a voltage into the secondary windings and creates a high voltage surge that is sent to the spark plug wire.

Scheme 7

Each cylinder has a double coil set, and its own dedicated spark plug wire. The coils are controlled by the PCM. The coils can be fired simultaneously or in phases. The coils are phase-shift triggered, firing plugs A-B, then B-A, then A-B etc. The offset between the plug firing varies from 0° to 10°. Timing can be retarded by as much as 14.5°.

Scheme 8

Scheme 9

Scheme 10

1. Disconnect the negative battery cable (2).
2. Remove the air cleaner inlet tubes (2).
3. Remove the engine cover (1). Grasp both corners of the engine cover, and pull up firmly.
4. Disconnect the ignition coil wire harness connector (1).
5. Disconnect the spark plug cables (4) from the spark plugs.
6. Remove the ignition coil retaining bolt (2).
7. Remove the ignition coil (3) from the cylinder head cover.

Scheme 11

Scheme 12

Scheme 13

1. Disconnect the negative battery cable (2).
2. Remove the engine cover (1). Grasp both corners of the engine cover, and pull up firmly.
3. Remove the upper air cleaner housing by removing the inlet tube (2) and the retaining screws (1). «(Refer to ENGINE/AIR INTAKE SYSTEM/AIR CLEANER HOUSING - REMOVAL)»(ref-250616-S02809968752007031500000) .
4. Disconnect the ignition coil harness connector (2).
5. Disconnect both the spark plug cables from the spark plugs (3).
6. Remove the ignition coil mounting bolt (1).
7. Remove the ignition coil from the engine.

Scheme 14

1. Position the ignition coil (3) on the cylinder head cover.
2. Install the ignition coil retaining bolt (2). Tighten the bolt to 8 N.m (71 in. lbs.).
3. Connect the ignition coil wire harness connector (1) to the coil pack. NOTE: When installing the spark plug cables, route the cables correctly. Failure to route the cables properly can cause improper spark plug phase-shift.
4. Install the spark plug cables to the appropriate coil tower (A & B) (coil side).
5. Install the spark plug cables to the appropriate spark plug location (G & K) (plug side). NOTE: Refer to the reference pad cast into the cylinder head cover to identify proper spark plug/spark plug cable orientation. NOTE: When installing spark plug cables, insure a positive connection is made. A snap should be felt when a good connection is made between the spark plug cable and the spark plug.
6. Insure a firm connection is made from the spark plug cables (2) to the spark plugs.
7. Install the engine cover (1). Align the engine cover retaining clips to the rubber mounts, and push down firmly to connect engine cover to rubber mounts. NOTE: To ease the installation of the engine cover, apply a small amount of lubricant to the engine cover rubber mounts.
8. Connect the negative battery cable.

Two knock sensors are used on the 3.2L V-6. Highly sensitive knock sensors can distinguish knocking conditions in individual cylinders and retard the ignition timing on the cylinders that are knocking. This anti-knock control prevents damage to the engine and allows operation on lower grade fuel, but only in emergencies. Premium grade fuel is required under normal operating conditions to ensure full power and economy. When the knock sensor detects a knock in one of the cylinders, the sensor sends an input signal to the Powertrain Control Module (PCM). In response, the PCM retards ignition timing for the affected cylinder.

The voltage signal produced by the knock sensor increases with the amplitude of vibration. The PCM receives the knock sensor voltage signal as an input. If the signal rises above a predetermined level, the PCM will store that value in memory and retard ignition timing to reduce engine knock. If the knock sensor voltage exceeds a preset value, the PCM retards ignition timing for all cylinders.

Knock sensors contain a piezoelectric material which constantly vibrates and sends an input voltage (signal) to the PCM while the engine operates. As the intensity of the crystal's vibration increases, the knock sensor output voltage also increases.

The PCM ignores knock sensor input during engine idle conditions. Once the engine speed exceeds a specified value, knock retard is allowed.

Note. Over tightening or under tightening the knock sensor mounting bolts will affect knock sensor performance, possibly causing improper spark control. Always use the specified torque when installing the knock sensors.

Scheme 15

1. Remove the intake manifold from the engine. «(Refer to ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL)»(ref-250615-S21099981312007031500000) for 3.2L - Service Information or «(Refer to ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL)»(ref-250616-S21258127192007031500000) for 3.2L SRT - Service Information .
2. Disconnect the wire harness connectors at the knock sensors (1).
3. Remove the retaining bolts.
4. Remove the knock sensors from the engine block.

The engine uses platinum tip resistor spark plugs. Platinum tip spark plugs allow 100,000-mile (161,000-km) replacement intervals in normal service. They have resistance values of 6,000 to 20,000 ohms when checked with at least a 1000 volt tester.

For spark plug identification and specifications, (Refer to ELECTRICAL/IGNITION CONTROL - SPECIFICATIONS) .

Do not use an ohm meter to check the resistance of the spark plugs. This will give an inaccurate reading.

Spark plugs using either a single or double platinum tips have a recommended service life of 100,000 miles for normal driving conditions per schedule A in this service information. The spark plugs have a recommended service life of 75,000 miles for severe driving conditions. A thin platinum pad is welded to the center electrode (2) ends. Extreme care must be used to prevent spark plug cross threading, incorrect gapping, and ceramic insulator damage during plug removal and installation.

Remove the spark plugs and examine them for burned electrodes and fouled, cracked or broken porcelain insulators. Keep the spark plugs arranged in the order in which they were removed from the engine. An isolated spark plug displaying an abnormal condition indicates that a problem exists in the corresponding cylinder.

Spark plugs that have low mileage may be cleaned and reused if not otherwise defective. Adjust the gap between the electrodes to 1.00 mm (.039 in.).

Always tighten spark plugs to the specified torque. Over tightening can cause distortion resulting in a change in the spark plug gap or damage to the cylinder head. Tighten the spark plugs to 28 N.m (21 ft. lbs.).

Scheme 16

The few deposits present on the spark plug will probably be light tan or slightly gray in color. This is evident with most grades of commercial gasoline. There will not be evidence of electrode burning. Gap growth will not average more than approximately 0.025 mm (.001 in) per 3200 km (2000 miles) of operation. Spark plugs that have normal wear (1) can usually be cleaned, have the gap set and then be installed.

Some fuel refiners in several areas of the United States have introduced a manganese additive (MMT) for unleaded fuel. During combustion, fuel with MMT causes the entire tip of the spark plug to be coated with a rust colored deposit (2). This rust color can be misdiagnosed as being caused by coolant in the combustion chamber. Spark plug performance may be affected by MMT deposits.

Always remove the spark plug cable by grasping the top of the spark plug insulator, turning the boot 1/2 turn and pulling straight up in a steady motion.

Failure to route the cables properly could cause improper phase-shifting of the spark plugs. Install spark plug insulators over spark plugs. Ensure the top of the spark plug insulator covers the upper end of the spark plug tube, then connect the other end to coil pack.