Cherokee 4WD LHD L6-4.0L VIN S (2001)
1. The coil is bolted directly to the cylinder head. One electrical connector (located at rear of coil) is used for all three coils.
Although cylinder firing order is the same as this engine of previous years, spark plug firing is not. The 3 coils dual-fire the spark plugs on
cylinders 1-6, 2-5 and/or 3-4. When one cylinder is being fired (on compression stroke), the spark to the opposite cylinder is being wasted (on
exhaust stroke).
Battery voltage is supplied to the three ignition coils from the ASD relay. The Powertrain Control Module (PCM) opens and closes the ignition
coil ground circuit 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. The cables are integral within the coil rail.