RAM 1500 Truck 4WD V8-5.9L VIN Z (2002)
Because of coil design, spark plug cables (secondary cables) are not used with the 3.7L engine.
Fig. 19 Ignition Coil Location - 4.7L
4.7L
The 4.7L V-8 engine uses 8 dedicated, and individually fired coil for each spark plug. Each coil is mounted directly to the top of each spark plug.
Battery voltage is supplied to the 8 individual ignition coils from the ASD relay. The Powertrain Control Module (PCM) opens and closes each
ignition coil ground circuit at a determined time for ignition coil operation.
Base ignition timing is not adjustable. By controlling the coil ground circuit, the PCM is able to set the base timing and adjust the ignition timing
advance. This is done to meet changing engine operating conditions.
The ignition coil is not oil filled. The windings are embedded in an epoxy compound. This provides heat and vibration resistance that allows the
ignition coil to be mounted on the engine.
Because of coil design, spark plug cables (secondary cables) are not used with the 4.7L engine.
