Ram Truck 1500, 2500 & 3500 (2006-2008)

5.7L (SMPI) Engine


The 5.7L V-8 engine is equipped with 16 spark plugs. Two plugs are used for each cylinder. The 5.7L is also equipped with 8 separate and independent ignition coils. The one-piece coil bolts directly to the cylinder head cover and attaches the coils secondary output terminal directly to a spark plug using a rubber boot seal. Each coil is also equipped with a second output terminal. This second terminal connects a conventional spark plug cable directly to a spark plug on the opposite cylinder bank. A separate primary electrical connector is used for each coil.

Eight conventional spark plug cables are used with the 5.7L. These cables connect a coil on one cylinder bank, directly to a spark plug on the opposite cylinder bank. The cables are placed and routed in a special plastic loom to keep them separated. This loom is clipped to the intake manifold. To prevent a miss-match of cables, a corresponding spark plug / coil number is displayed on each plug cable: 1/6, 2/3, 4/7 and 5/8. These numbers can also be found on the top of the intake manifold to the right of the throttle body.

Two knock sensors (one for each cylinder bank) are used to help control spark knock.

The ignition system consists of:

16 Spark Plugs (2 per cylinder)
8 Separate, Dual-Secondary Output, Ignition Coils
2 Knock Sensors
8 Secondary Ignition Cables
Powertrain Control Module (PCM)
Also to be considered part of the ignition system are certain inputs from the Crankshaft position, Camshaft position, Throttle position, and MAP Sensor.